Name: high-sensitivity nuclear magnetic resonance at giga-pascal pressures: a new tool for probing electronic and chemical properties of condensed matter under extreme conditions
Uploaded: 2014-10-10T15:00:00.000+00:00
Duration: 8 min 42 s
Description: Watch this Scientific Journal Video about High-Sensitivity Nuclear Magnetic Resonance at Giga-Pascal Pressures: A New Tool for Probing Electronic and Chemical Properties of Condensed Matter under Extr

This research was funded by the International Research Training Group (IRTG) &#8220;Diffusion in porous Materials&#8221;. We acknowledge the technical support from Gert Klotzsche and stimulating discussions with Steven Reichhardt, Thomas Meissner, Damian Rybicki, Tobias Herzig, Natalya Georgieva, Jonas Kohlrautz, and Michael Jurkutat.

1. Montage und Ausrichtung der 6H-SiC großen Kegel Böhler-Typ Ambosse <ol><li> Befestigen Sie den Kolben und xy Platte in der Montagewerkzeuge und legen Sie die Böhler-Typ Ambosse in der Sitzecke. </li><li> Stellen Sie sicher, jeder Amboß sitzt fest in der Trägerplatten. </li><li> Mit Epoxidharz, (zB Stycast 1266), kleben Sie beide Ambosse auf ihre Plätze. Heilmittel für 12 h bei RT oder 65 ° C in einem Ofen für 2 Stunden. </li><li> Für eine ausreichende Amboß-Ausrichtungs, verwenden Sie die M1 Stellschrauben, um die Trägerplatten ausrichten und überwachen die Parallelität der beiden Ambosse. Wenn die Ambosse wurden nicht parallel zu sein, entfernen Sie das Epoxidharz und starten Sie bei Punkt 1.2. </li></ol> 2. Dichtung Vorbereitung <ol><li> Bohrer 1 mm Löcher in einen Chip von geglüht Cu-Be-(Cu 98% w, Be 2 Gew%, Dicke von 0,5 mm) für die Führungsstifte aus Messing. </li><li> Legen Sie drei 5 mm lange Stücke von 1 mm Durchmesser nicht isolierten Kupferdraht in die Löcher, die sich entlang der Amboss verteilt sind, dienen als GUIDe Pins für die Cu-Be-Dichtung. </li><li> Überprüfen Sie die korrekte Erdung zwischen den Führungsstiften und der Zellkörper. Typischerweise wird ein Gleichstromwiderstand von etwa 0,1 Ω Wunsch. Verbesserung mit einer Anwendung einer geringen Menge von leitfähigen Silber. </li><li> Legen Sie die Cu-Be-Chip auf der moissanite Amboss und schließen Sie die Zelle. </li><li> Verwendung einer hydraulischen Presse, die Dichtung unter Druck zu setzen, um zu 1/8 der culet Durchmesser für maximale Betriebsstabilität. Überwachung der tatsächlichen Dicke der Vertiefung unter Verwendung eines Mikrometermessschieber. </li><li> Bohren Sie ein Loch von dem entsprechenden Durchmesser (½ der culet Durchmesser) in der Mitte der Vertiefung. </li><li> Schnitzen zwei Kanäle in die Pre-rückt Dichtung. Die Kanäle sollten tief genug, um die 18 um Kupferdraht der Mikrospule aufzunehmen. </li><li> Härten die hergestellte Dichtung bei 617 K für 2 bis 3 h in einem Ofen. </li></ol> 3. Vorbereitung und Beladung der Mikrospule <ol><li> Verwenden Sie ein Stück von 1 mm Kupferdraht eind wird durch das Durchgangsgewinde des Kolbens. Befestigen Sie den Kupferdraht mit Epoxid-Harz und heilen nach Schritt 1.3. </li><li> Wählen Sie eine Ahle (siehe Liste der Materialien), die den gewünschten Durchmesser der Mikrospule und befestigen Sie es zwischen einem Paar von drehbaren Spannfutter-Backen. </li><li> Kleber (mit zB Lack von SCB, siehe Liste der Materialien) ein Ende des 18 um Kupferdraht auf die Spannbacken, während das andere Ende hält und drehen Sie die Spannbacken, so dass der Draht auf die Ahle aufgerollt. </li><li> Wenn der Mikrospule aus der gewünschten Geometrie, Das andere Ende des Drahtes auf den Leim auch. </li><li> Mit verdünntem Lack, um die Spule, indem eine kleine Menge auf der Wicklungen zu beheben. </li><li> Entfernen Sie die Spule vorsichtig von der Ahle mit Teflonband. </li><li> Platzieren Sie einige Epoxidharz (siehe Punkt 1.3), ohne jegliche Zusätze, die in den Kanälen der Dichtung. </li><li> Legen Sie die Mikrospule innerhalb der Probenkammer und befestigen Sie die Kabel in die Kanäle. </li><li> Heilung der EPoXy Harz gemäß Schritt 1.3. </li><li> Löt einem Vorsprung des Mikrospule mit dem heißen Draht und die andere mit einem Führungszapfen. </li><li> Fügen Sie etwas Silber leitende Paste auf der jeweils Kreuzung. Die Aushärtung dauert in der Regel einige Minuten. </li><li> Abzudichten beide Übergänge mit einer geringen Menge von Epoxidharz. </li><li> Heilung der Epoxy gemäß Schritt 1.3. </li><li> Nun überprüfen Sie die Gleichstromwiderstand der Spule nach jedem Schritt. </li><li> Legen Sie die Probe in der Mikro-Spule. Seien Sie sich bewusst, dass jede unnötige Körperkontakt kann die Spule zu zerstören. </li><li> Fügen Sie fein gemahlene Pulver Rubin zur Probe für die Druckkalibrierung. </li><li> Schließlich überschwemmen die Probenkammer mit einem geeigneten Druckmedium. Verwenden Paraffinöl auf fast-hydrostatischen Bedingungen bis zu 9 GPa gewährleisten. </li><li> Küvette sorgfältig. </li></ol> 4. Anwendung und Überwachung von Druck <ol><li> Auf den ersten, leicht die M3 Allen versenkten Schrauben festziehen. </li><li> Für Druck fixieren die Zelle in einen Schraubstock einspannen. Nun ziehenzwei gegenüberliegende Schrauben paarweise. </li><li> Platzieren Sie den Druck Zelle in einem geeigneten Zellenhalter. </li><li> Einstellen der Position der Zelle, so daß der Laserstrahl in die Probenkammer gelangt. </li><li> Verwenden Sie die Feineinstellung Tabelle, um die Ruby-Pulver in den Laserstrahl konzentrieren. </li><li> Überwachen Sie die Rubin Photolumineszenzspektrum mit der entsprechenden Software-Spektrometer. </li><li> Entpacken Sie die aktuellen Druck in der Probenraum von der beobachteten spektralen Verschiebung der Rubin R1 und R2 Linien. </li><li> Äquilibrieren das Druckzelle für mindestens 12 h vor der NMR-Messungen gestartet. </li></ol> 5. Darstellende NMR-Experimente <ol><li> Montieren Sie die Druckzelle auf einem typischen NMR-Sonde. Herstellung geeignete Zellhalter in einer mechanischen Werkstatt. </li><li> Löten Sie den heißen Draht zu der Sonde. Überprüfen Sie den elektrischen Kontakt zwischen der Zelle und der Sonde. </li><li> Jetzt, führen Standard-NMR-Experimente. Die Aufmerksamkeit auf die Tatsache, dass die Mikrospule ist very empfindlich auf die angelegte Hochfrequenzleistung. </li></ol>

<ol>
	<li>Hemley, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Percy+Bridgman&#180;s+Second+Century.">Percy Bridgman&#180;s Second Century.</a> High Pressure Research. 30 (4), 581-619 (2010).</li><li>Grochala, W., Hoffmann, R., Feng, J., Ashcroft, N. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Chemical+imagination+at+work+in+very+tight+places.">The Chemical imagination at work in very tight places.</a> Angewandte Chemie (International Edition in English). 46 (20), 3620-3642 (2007).</li><li>Ma, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transparent+dense+sodium.">Transparent dense sodium.</a> Nature. 458 (7235), 182-185 (2009).</li><li>Eremets, M. I., Troyan, I. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conductive+dense+hydrogen.">Conductive dense hydrogen.</a> Nat Mater. 10 (12), 927-931 (2011).</li><li>Jayaraman, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diamond+anvil+cell+and+high-pressure+physical+investigations.">Diamond anvil cell and high-pressure physical investigations.</a> Rev Mod Phys. 55 (1), 65-108 (1983).</li><li>Bertani, R., Mali, M., Roos, J., Brinkmann, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+diamond+anvil+cell+for+high-pressure+NMR+investigations.">A diamond anvil cell for high-pressure NMR investigations.</a> Rev Sci Instrum. 63 (6), 3303 (1992).</li><li>Lee, S. -. H., Luszczynski, K., Norberg, R. E., Conradi, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NMR+in+a+diamond+anvil+cell.">NMR in a diamond anvil cell.</a> Rev Sci Instrum. 58 (3), 415 (1987).</li><li>Lee, S. -. H., Conradi, M. S., Norberg, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+NMR+resonator+for+diamond+anvil+cells.">Improved NMR resonator for diamond anvil cells.</a> Rev Sci Instrum. 63 (7), 3674 (1992).</li><li>Pravica, M. G., Silvera, I. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nuclear+magnetic+resonance+in+a+diamond+anvil+cell+at+very+high+pressures.">Nuclear magnetic resonance in a diamond anvil cell at very high pressures.</a> Rev Sci Instrum. 69 (2), 479 (1998).</li><li>Lee, S. -. H., Conradi, M., Norberg, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+motion+in+solid+H2+at+high+pressures.">Molecular motion in solid H2 at high pressures.</a> Phys Rev B. 40 (18), 12492-12498 (1989).</li><li>Vaughan, R. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+Apparatus+for+Magnetic+Measurements+at+High+Pressure.">An Apparatus for Magnetic Measurements at High Pressure.</a> Rev Sci Instrum. 42 (5), 626 (1971).</li><li>Yarger, J. L., Nieman, R. A., Wolf, G. H., Marzke, R. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-Pressure+1H+and+13C+Nuclear+Magnetic+Resonance+in+a+Diamond+Anvil+Cell.">High-Pressure 1H and 13C Nuclear Magnetic Resonance in a Diamond Anvil Cell.</a> Journal of Magnetic Resonance Series A. 114 (2), 255-257 (1995).</li><li>Okuchi, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+type+of+nonmagnetic+diamond+anvil+cell+for+nuclear+magnetic+resonance+spectroscopy.">A new type of nonmagnetic diamond anvil cell for nuclear magnetic resonance spectroscopy.</a> Physics of the Earth and Planetary Interiors. , 143-144 (2004).</li><li>Kluthe, S., Markendorf, R., Mali, M., Roos, J., Brinkmann, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pressure-dependent+Knight+shift+in+Na+and+Cs+metal.">Pressure-dependent Knight shift in Na and Cs metal.</a> Phys Rev B. 53 (17), 11369-11375 (1996).</li><li>Graf, D. E., Stillwell, R. L., Purcell, K. M., Tozer, S. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nonmetallic+gasket+and+miniature+plastic+turnbuckle+diamond+anvil+cell+for+pulsed+magnetic+field+studies+at+cryogenic+temperatures.">Nonmetallic gasket and miniature plastic turnbuckle diamond anvil cell for pulsed magnetic field studies at cryogenic temperatures.</a> High Pressure Research. 31 (4), 533-543 (2011).</li><li>Pravica, M., Silvera, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NMR+Study+of+Ortho-Para+Conversion+at+High+Pressure+in+Hydrogen.">NMR Study of Ortho-Para Conversion at High Pressure in Hydrogen.</a> Physical Review Letters. 81 (19), 4180-4183 (1998).</li><li>Haase, J., Goh, S. K., Meissner, T., Alireza, P. L., Rybicki, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+sensitivity+nuclear+magnetic+resonance+probe+for+anvil+cell+pressure+experiments.">High sensitivity nuclear magnetic resonance probe for anvil cell pressure experiments.</a> Rev Sci Instrum. 80 (7), 73905 (2009).</li><li>Meissner, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+Approach+to+High-Pressure+Nuclear+Magnetic+Resonance+with+Anvil+Cells.">New Approach to High-Pressure Nuclear Magnetic Resonance with Anvil Cells.</a> J Low Temp Phys. 159 (1-2), 284-287 (2010).</li><li>Meier, T., Herzig, T., Haase, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Moissanite+Anvil+Cell+Design+for+Giga-Pascal+Nuclear+Magnetic+Resonance.">Moissanite Anvil Cell Design for Giga-Pascal Nuclear Magnetic Resonance.</a> Rev Sci Instrum. 85 (4), 43903 (2014).</li><li>Boyer, R. F., Collings, E. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Materials Properties Handbook: Titanium Alloys. , (1994).</li><li>Xu, J. -. a., Yen, J., Wang, Y., Huang, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrahigh+pressures+in+gem+anvil+cells.">Ultrahigh pressures in gem anvil cells.</a> High Pressure Research. 15 (2), 127-134 (1996).</li><li>Xu, J. -. a., Mao, H. -. k., Hemley, R. J., Hines, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+moissanite+anvil+cell+a+new+tool+for+high-pressure+research.">The moissanite anvil cell a new tool for high-pressure research.</a> J Phys Condens Matter. 14 (44), 11543-11548 (2002).</li><li>Xu, J. -. a., Mao, H. -. k., Hemley, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+gem+anvil+cell+high-pressure+behaviour+of+diamond+and+related+materials.">The gem anvil cell high-pressure behaviour of diamond and related materials.</a> J Phys Condens Matter. 14 (44), 11549-11552 (2002).</li><li>Meissner, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nuclear+magnetic+resonance+at+up+to+10.1+GPa+pressure+detects+an+electronic+topological+transition+in+aluminum+metal.">Nuclear magnetic resonance at up to 10.1 GPa pressure detects an electronic topological transition in aluminum metal.</a> J Phys Condens Matter. 26 (1), 15501 (2014).</li><li>Meissner, T., Goh, S. K., Haase, J., Williams, G. r. a. n. t. . V. M., Littlewood, P. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-pressure+spin+shifts+in+the+pseudogap+regime+of+superconducting+YBa2Cu4O8+as+revealed+by+17O+NMR.">High-pressure spin shifts in the pseudogap regime of superconducting YBa2Cu4O8 as revealed by 17O NMR.</a> Phys Rev B. 83 (22), (2011).</li><li>Goh, S. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+pressure+de+Haas&#8211;van+Alphen+studies+of+Sr2RuO4+using+an+anvil+cell.">High pressure de Haas&#8211;van Alphen studies of Sr2RuO4 using an anvil cell.</a> Current Applied Physics. 8 (3-4), 304-307 (2008).</li><li>Tateiwa, N., Haga, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluations+of+pressure-transmitting+media+for+cryogenic+experiments+with+diamond+anvil+cell.">Evaluations of pressure-transmitting media for cryogenic experiments with diamond anvil cell.</a> Rev Sci Instrum. 80 (12), 123901 (2009).</li><li>Hahn, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spin+Echoes.">Spin Echoes.</a> Phys Rev. 80 (4), 580-594 (1950).</li><li>Boehler, R., Ross, M., Boercker, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Melting+of+LiF+and+NaCl+to+1+Mbar+Systematics+of+Ionic+Solids+at+Extreme+Conditions.">Melting of LiF and NaCl to 1 Mbar Systematics of Ionic Solids at Extreme Conditions.</a> Physical Review Letters. 78 (24), 4589-4592 (1997).</li><li>Funamori, N., Sato, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+cubic+boron+nitride+gasket+for+diamond-anvil+experiments.">A cubic boron nitride gasket for diamond-anvil experiments.</a> Rev Sci Instr. 79 (5), 053903 (2008).</li><li>Forman, R. A., Piermarini, G. J., Barnett, J. D., Block, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pressure+measurement+made+by+the+utilization+of+ruby+sharp-line+luminscence.">Pressure measurement made by the utilization of ruby sharp-line luminscence.</a> Science. 176 (4032), 284-285 (1972).</li></ol>

The authors have nothing to disclose.

Eine neue und vielversprechende Methode, um NMR bei Giga-Pascal Druck durchzuführen wurde beschrieben. Diese Methode öffnet die Tür zu einer Vielzahl von NMR-Experimente durch seine hervorragende Empfindlichkeit und Auflösung. Dennoch sind mehrere in der Protokoll Abschnitt beschriebenen Schritte für den Ausgang des Experiments. Insbesondere ist die Herstellung der Mikrospule und deren Fixierung in der Cu-Be-Dichtung sehr schwierig und erfordert einige Erfahrung. Im Folgenden sind einige wichtige Tipps gegeben, was...

Da Percy Bridgman Markenzeichen Experimente der kondensierten Materie unter hohen hydrostatischen Drücke am Anfang des letzten Jahrhunderts hat sich das Feld der Hochdruckphysik schnell 1 entwickelt. Eine große Anzahl von interessanten Phänomene sind bekannt, unter Drücken von einigen GPa 2 auftreten. Darüber hinaus hat die Reaktion der Systeme kondensierter Materie mit Hochdruck uns viel über ihre elektronischen Grundzustand und angeregten Zuständen 3,4 unterrichtet. Leider sind Techniken für die Untersuchung der elektronischen Eigenschaften von kondensierter Materie bei Giga-Pascal Druck selten, mit x-ray-oder DC-Widerstandsmessungen den Weg 5. Insbesondere wird die Erfassung der elektronischen oder magnetischen Kernmomente mit Elektronenspin (ESR) oder Kernspinresonanz (NMR)-Experimente, gebunden zu sein, fast unmöglich, in einem typischen Hochdruck-Amboss-Zellen, wo man das Signal abrufen muss umsetzen ein kleines volume durch Ambosse und einer Dichtung verankert. Mehrere Gruppen haben versucht, dieses Problem durch die Verwendung komplexer Arrangements, lösen zB zwei Split-Pair-Radiofrequenz (RF)-Spulen entlang der Flanken der Ambosse 6 aufgewickelt, ein Einzel-oder Doppelschleife Haarnadel-Resonator 7,8; . oder sogar eine Spaltung Rhenium Dichtung als HF-Pick-up-Spule 9, siehe Abbildung 1 Leider sind diese Ansätze noch von einem niedrigen Signal-zu-Rausch-Verhältnis (SNR) gelitten, die Begrenzung der experimentelle Anwendungen zu großen - γ Kerne wie 1 H 10. 15 - Der interessierte Leser kann auf andere Hochdruck-Schwingkreis 11 Experimente bezeichnet werden. Pravica und Silvera 16 Bericht der höchste Druck in einer Druckzelle für die NMR mit 12,8 GPa, der die ortho-para-Umwandlung von Wasserstoff untersucht erreicht. Mit großem Interesse bei der Anwendung NMR, um die Eigenschaften der Quantenfestkörper zu untersuchen, war unsere Gruppe interessiert, NMR erhältlich bei hohen Drücken, wie gut. Schließlich im Jahr 2009 konnte gezeigt werden, dass mit hoher Empfindlichkeit Tempelzelle NMR ist in der Tat möglich, wenn eine Resonanz Radiofrequenz (RF)-Mikrospule direkt in der Hochdruckkammer 17 umschließt die Probe gestellt. Bei einem solchen Ansatz wird die NMR-Empfindlichkeit um mehrere Größenordnungen (hauptsächlich wegen der dramatischen Zunahme Füllfaktor der HF-Spule), die noch schwieriger NMR-Experimente möglich, zB an Pulverproben eine verbesserte, 17 O-NMR Hochtemperatur-Supraleiter mit bis zu 7 GPa 18. Supraleitung in diesen Materialien kann durch die Anwendung von Druck verstärkt werden, und es ist nun möglich, diesen Prozess mit einer lokalen elektronischen Sonde, die grundlegenden Einblick in die Steuerungsprozesse verspricht folgen. Ein weiteres Beispiel für die Macht der NMR unter hohem Druck entstanden, was waren Believed Routine Referenzierung Experimente: Um die eingeführte neue Tempelzelle NMR zu testen, eine der besten bekannten Materialien wurde gemessen - einfache Aluminium-Metall. Als der Druck erhöht wurde, war eine unerwartete Abweichung der NMR-Verschiebung von dem, was man für einen Freie-Elektronen-System erwarten gefunden. Unter erhöhtem Druck wiederholte Versuche, auch zeigte, dass die neuen Ergebnisse waren in der Tat zuverlässig. Schließlich mit Bandstruktur Berechnungen wurde dann festgestellt, dass die Ergebnisse der Manifestation einer topologischen Übergang des Fermi-Oberfläche von Aluminium, die vor Jahren nicht durch Berechnungen nachgewiesen werden, wenn die Rechenleistung niedrig war. Extrapolation der Ergebnisse an die Umgebungsbedingungen zeigten, dass die Eigenschaften dieses Metalls, die fast überall verwendet wird, werden von dieser speziellen elektronischen Zustand beeinflusst. Um eine Reihe von verschiedenen Anwendungen zu verfolgen hatte speziell Tempelzellen (Zellen, die aus dem vorherigen Cavend importiertish Labor und für die NMR nachgerüstet) entwickelt worden. Derzeit sind die verwendeten selbst gebaute Chassis der Lage zu erreichen Drücke bis 25 GPa mit einem Paar 800 um culet 6H-SiC Ambosse. NMR-Experimente wurden erfolgreich auf 10,1 GPa, so weit durchgeführt. Die NMR-Leistung dieses neuen Zellen wurde gezeigt, gut 19 ​​sein. Die Hauptkomponente ist Titan-Aluminium-(6) -Vanadium (4) mit einem extra niedrigen interstitiellen Stufe (Klasse 23), wodurch eine Streckgrenze von 800 MPa über 20. Aufgrund seiner nicht-magnetischen Eigenschaften (die magnetische Suszeptibilität χ etwa 5 ppm) es eine ausreichende Material für die Druckzelle Chassis ist. Die Abmessungen der eingesetzten Zellen (siehe Abbildung 2 für einen Überblick über alle selbst gebaute Tempelzelle Designs) sind klein genug, um in reguläre Standardbohrung NMR Magneten passen. Die kleinste Design, die LAC-TM1, die nur 20 mm in der Höhe und 17 mm im Durchmesser ist, passt typischen kleinen Kalt Bohrung Magneten (30 mm Bohrungsdurchmesser). Die LAC-TM2, die neuesten Chassis die Autoren konzipiert ist, arbeitet mit vier M4 Allen Senker Schrauben als Druckantriebsmechanismus (aus der gleichen Legierung wie die Zelle Chassis gemacht), so dass für eine reibungslose Steuerung der Innendruck (Blaupausen in der beigefügten Zusatz Abschnitt). Typischerweise werden Diamant Ambosse verwendet, um höchsten Drücke von über 100 GPa zu erzeugen. Xu und Mao 21. - 23. haben gezeigt, dass moissanite Ambosse eine kostengünstige Alternative in Hochdruck-Forschung, bis zu Drücken von etwa 60 GPa. Daher wurden für die Ambosse moissanite eingeführt GPa NMR-Ansatz verwendet. Die besten Ergebnisse wurden mit maßgeschneiderten großen Kegel 6H-SiC Ambosse vom Amboss-Abteilung von Charles &amp; Colvard erreicht. Mit diesen Zellen, für Drücke bis 10,1 GPa, die Verwendung von 800 um culet Ambossen wurde gefunden, in sehr guten NMR Empfindlichkeit führen. Zum Vergleich, Lee et al. Berichten über einen SNR von 1 1 H NMR Leitungswasser, während das SNR des eingeführten Mikrospule Ansatz zeigte einen Wert von 25 für 1/7 ihres Volumens, selbst bei einer etwas niedrigeren Magnetfeld. Mit diesem neuen Ansatz zur hochempfindlichen Tempelzelle NMR kann man viele Anwendungen, die spannende neue Einblicke in die Physik und Chemie der modernen Materialien versprechen zu verfolgen. Aber wie immer, Empfindlichkeit und Auflösung letztlich begrenzen die Anwendung der NMR, insbesondere dann, wenn man sich für viel höhere Drücke, die kleiner culet Größen fordern ist. Dann hat man nicht nur die Zellenkonstruktion mit noch kleineren HF-Spulen zu optimieren, sondern auch darüber nachdenken, Verfahren zur Erhöhung der Kernpolarisation.

<table><tbody><tr><td>Titanium grade 23</td><td>robemetall GmbH</td><td>ASTM F 136</td><td></td></tr><tr><td>Beryllium copper foil</td><td>GoodFellow</td><td>CU070501</td><td>Alloy 25 (C17200)</td></tr><tr><td>Copper wire for micro-coil</td><td>Polyfil</td><td></td><td>quote on inquiry</td></tr><tr><td>Stycast 1266</td><td>Sil-Mid Ldt.</td><td>S1266001KG</td><td></td></tr><tr><td>Moissanite anvils</td><td>Charles &amp;amp; Colvard</td><td></td><td>quote on inquiry</td></tr><tr><td>Paraffin oil (pressure medium)</td><td>Sigma Aldrich</td><td>18512-1L</td><td></td></tr><tr><td>M4 Allen contersunk screws (Ti64)</td><td>Der Schraubenladen</td><td>DIN912 M4x20</td><td></td></tr><tr><td>Optiprexx PLS</td><td>Almax-easylab</td><td></td><td>quote on inquiry</td></tr><tr><td>Ruby spheres (~10-50 &amp;micro;m)</td><td>DiamondAnvils.com</td><td>P00996</td><td></td></tr><tr><td>Manual Toggle Press</td><td>DiamondAnvils.com</td><td>A87000</td><td></td></tr><tr><td>Gasket Thickness Micrometer</td><td>DiamondAnvils.com</td><td>A86000</td><td></td></tr><tr><td>Titanium Scalpel&amp;nbsp;</td><td>Newmatic Medical</td><td>NM45200710421&amp;nbsp;</td><td></td></tr><tr><td>Glass-writing Diamond</td><td>Plano</td><td>54467</td><td></td></tr><tr><td>Smoothing Awls</td><td>Flume</td><td>1 4444 001</td><td></td></tr><tr><td>Chuck-jaws (4 jaws)</td><td>Flume</td><td>4 561 289</td><td></td></tr><tr><td>Lathe</td><td>Flume</td><td>4 560 023</td><td></td></tr><tr><td>Drilling Machine</td><td>Flume</td><td>4 570 020</td><td></td></tr><tr><td>Drill chuck</td><td>Flume</td><td>4 570 021</td><td></td></tr><tr><td>XY stage</td><td>Flume</td><td>4 570 022</td><td></td></tr><tr><td>Drills (0.30 to 0.50 mm)</td><td>Flume</td><td>4 572 652 &amp;ndash; 654</td><td></td></tr><tr><td>Low Temperature Varnish</td><td>SCBshop</td><td>SCBltv03</td><td></td></tr></tbody></table>

high-sensitivity nuclear magnetic resonance at giga-pascal pressures: a new tool for probing electronic and chemical properties of condensed matter under extreme conditions

Nuclear Magnetic Resonance (NMR) is one of the most important techniques for the study of condensed matter systems, their chemical structure, and their electronic properties. The application of high pressure enables one to synthesize new materials, but the response of known materials to high pressure is a very useful tool for studying their electronic structure and developing theories. For example, high-pressure synthesis might be at the origin of life; and understanding the behavior of small molecules under extreme pressure will tell us more about fundamental processes in our universe. It is no wonder that there has always been great interest in having NMR available at high pressures. Unfortunately, the desired pressures are often well into the Giga-Pascal (GPa) range and require special anvil cell devices where only very small, secluded volumes are available. This has restricted the use of NMR almost entirely in the past, and only recently, a new approach to high-sensitivity GPa NMR, which has a resonating micro-coil inside the sample chamber, was put forward. This approach enables us to achieve high sensitivity with experiments that bring the power of NMR to Giga-Pascal pressure condensed matter research. First applications, the detection of a topological electronic transition in ordinary aluminum metal and the closing of the pseudo-gap in high-temperature superconductivity, show the power of such an approach. Meanwhile, the range of achievable pressures was increased tremendously with a new generation of anvil cells (up to 10.1 GPa), that fit standard-bore NMR magnets. This approach might become a new, important tool for the investigation of many condensed matter systems, in chemistry, geochemistry, and in physics, since we can now watch structural changes with the eyes of a very versatile probe.

Figur 3 zeigt, wie die komplett montierte Druckzelle, die Verdrahtung und die Montage auf einem typischen NMR-Sonde aussehen. Im Folgenden werden verschiedene Experimente überprüft werden, welche der Leser sollte einen breiten Überblick über die Vorteile und Grenzen der Technik eingeführt sammeln. <img alt="Figur 1" src="/files/ftp_upload/52243/52243fig1highres.jpg" /> Abbildung 1. Verschiedene Ansätze für Hochdruck-N...

Watch this Scientific Journal Video about High-Sensitivity Nuclear Magnetic Resonance at Giga-Pascal Pressures: A New Tool for Probing Electronic and Chemical Properties of Condensed Matter under Extr

High-Sensitivity Nuclear Magnetic Resonance at Giga-Pascal Pressures: A New Tool for Probing Electronic and Chemical Properties of Condensed Matter under Extreme Conditions

Nuclear magnetic resonance is one of the most important spectroscopic tools. Here, the development of a new approach under high pressure, currently up to 10.1 GPa, is presented. This opens a new window into condensed matter physics and chemistry, where high-pressure research is of great importance.

High-Sensitivity Nuclear Magnetic Resonance bei Giga-Pascal Drücke: ein neues Instrument zur Sondierung elektronischen und chemischen Eigenschaften von kondensierter Materie unter extremen Bedingungen

Nuclear Magnetic Resonance (NMR) is one of the most important techniques for the study of condensed matter systems, their chemical structure, and their ...

high-sensitivity-nuclear-magnetic-resonance-at-giga-pascal-pressures

Research

Education

JoVE Core

JoVE Journal

Analytical Chemistry

Engineering

Unit 1

Principles of Nuclear Magnetic Resonance

SCIENTISTS IN ACTION

11.5K Aufrufe.  University of Leipzig. Nuclear magnetic resonance is one of the most important spectroscopic tools. Here, the development of a new approach under high pressure, currently up to 10.1 GPa, is presented. This opens a new window into condensed matter physics and chemistry, where high-pressure research is of great importance.

Serie: High-Sensitivity Nuclear Magnetic Resonance at Giga-Pascal Pressures: A New Tool for Probing Electronic and Chemical Properties of Condensed Matter under Extreme Conditions

Hyperpolarized Xenon for NMR and MRI Applications

Nuclear magnetic resonance (NMR) spectroscopy and imaging (MRI) suffer from intrinsic low sensitivity because even strong external magnetic fields of ~10 T generate only a small detectable net-magnetization of the sample at room temperature 1. Hence, most NMR and MRI applications rely on the detection of molecules at relative high concentration (e.g., water for imaging of biological tissue) or require excessive acquisition times. This limits our ability to exploit the very useful molecular specificity of NMR signals for many biochemical and medical applications. However, novel approaches have emerged in the past few years: Manipulation of the detected spin species prior to detection inside the NMR/MRI magnet can dramatically increase the magnetization and therefore allows detection of molecules at much lower concentration 2.
Here, we present a method for polarization of a xenon gas mixture (2-5% Xe, 10% N2, He balance) in a compact setup with a ca. 16000-fold signal enhancement. Modern line-narrowed diode lasers allow efficient polarization 7 and immediate use of gas mixture even if the noble gas is not separated from the other components. The SEOP apparatus is explained and determination of the achieved spin polarization is demonstrated for performance control of the method.
The hyperpolarized gas can be used for void space imaging, including gas flow imaging or diffusion studies at the interfaces with other materials 8,9. Moreover, the Xe NMR signal is extremely sensitive to its molecular environment 6. This enables the option to use it as an NMR/MRI contrast agent when dissolved in aqueous solution with functionalized molecular hosts that temporarily trap the gas 10,11. Direct detection and high-sensitivity indirect detection of such constructs is demonstrated in both spectroscopic and imaging mode.

The production of hyperpolarized xenon by means of spin exchange optical pumping (SEOP) is described. This method yields a ~10000-fold enhancement of the nuclear spin polarization of Xe-129 and has applications in nuclear magnetic resonance spectroscopy and imaging. Examples of gas phase and solution state experiments are given.

Hyperpolarisiertem Xenon für NMR-und MRI-Anwendungen

Nuclear magnetic resonance (NMR) spectroscopy and imaging (MRI) suffer from intrinsic low sensitivity because even strong external magnetic fields of ~10 ...

Forschung

Ingenieurwesen

Synthesis and Microdiffraction at Extreme Pressures and Temperatures

High pressure compounds and polymorphs are investigated for a broad range of purposes such as determine structures and processes of deep planetary interiors, design materials with novel properties, understand the mechanical behavior of materials exposed to very high stresses as in explosions or impacts. Synthesis and structural analysis of materials at extreme conditions of pressure and temperature entails remarkable technical challenges. In the laser heated diamond anvil cell (LH-DAC), very high pressure is generated between the tips of two opposing diamond anvils forced against each other; focused infrared laser beams, shined through the diamonds, allow to reach very high temperatures on samples absorbing the laser radiation. When the LH-DAC is installed in a synchrotron beamline that provides extremely brilliant x-ray radiation, the structure of materials under extreme conditions can be probed in situ. LH-DAC samples, although very small, can show highly variable grain size, phase and chemical composition. In order to obtain the high resolution structural analysis and the most comprehensive characterization of a sample, we collect diffraction data in 2D grids and combine powder, single crystal and multigrain diffraction techniques. Representative results obtained in the synthesis of a new iron oxide, Fe4O5 1 will be shown.

The laser heated diamond anvil cell combined with synchrotron micro-diffraction techniques allows researchers to explore the nature and properties of new phases of matter at extreme pressure and temperature (PT) conditions. Heterogeneous samples can be characterized in situ under high pressure by 2D mapping and combined powder, single-crystal and multigrain diffraction approaches.

Synthese und Mikrodiffraktion bei extremen Drücken und Temperaturen

High pressure compounds and polymorphs are investigated for a broad range of purposes such as determine structures and processes of deep planetary ...

Simulation of the Planetary Interior Differentiation Processes in the Laboratory

A planetary interior is under high-pressure and high-temperature conditions and it has a layered structure. There are two important processes that led to that layered structure, (1) percolation of liquid metal in a solid silicate matrix by planet differentiation, and (2) inner core crystallization by subsequent planet cooling. We conduct high-pressure and high-temperature experiments to simulate both processes in the laboratory. Formation of percolative planetary core depends on the efficiency of melt percolation, which is controlled by the dihedral (wetting) angle. The percolation simulation includes heating the sample at high pressure to a target temperature at which iron-sulfur alloy is molten while the silicate remains solid, and then determining the true dihedral angle to evaluate the style of liquid migration in a crystalline matrix by 3D visualization. The 3D volume rendering is achieved by slicing the recovered sample with a focused ion beam (FIB) and taking SEM image of each slice with a FIB/SEM crossbeam instrument. The second set of experiments is designed to understand the inner core crystallization and element distribution between the liquid outer core and solid inner core by determining the melting temperature and element partitioning at high pressure. The melting experiments are conducted in the multi-anvil apparatus up to 27 GPa and extended to higher pressure in the diamond-anvil cell with laser-heating. We have developed techniques to recover small heated samples by precision FIB milling and obtain high-resolution images of the laser-heated spot that show melting texture at high pressure. By analyzing the chemical compositions of the coexisting liquid and solid phases, we precisely determine the liquidus curve, providing necessary data to understand the inner core crystallization process.

The high-pressure and high-temperature experiments described here mimic planet interior differentiation processes. The processes are visualized and better understood by high-resolution 3D imaging and quantitative chemical analysis.

Simulation der Planeteninnendifferenzierungsprozesse im Labor

A planetary interior is under high-pressure and high-temperature conditions and it has a layered structure. There are two important processes that led to ...

Dissolution Dynamic Nuclear Polarization Instrumentation for Real-time Enzymatic Reaction Rate Measurements by NMR

The main limitation of NMR-based investigations is low sensitivity. This prompts for long acquisition times, thus preventing real-time NMR measurements of metabolic transformations. Hyperpolarization via dissolution DNP circumvents part of the sensitivity issues thanks to the large out-of-equilibrium nuclear magnetization stemming from the electron-to-nucleus spin polarization transfer. The high NMR signal obtained can be used to monitor chemical reactions in real time. The downside of hyperpolarized NMR resides in the limited time window available for signal acquisition, which is usually on the order of the nuclear spin longitudinal relaxation time constant, T1, or, in favorable cases, on the order of the relaxation time constant associated with the singlet-state of coupled nuclei, TLLS. Cellular uptake of endogenous molecules and metabolic rates can provide essential information on tumor development and drug response. Numerous previous hyperpolarized NMR studies have demonstrated the relevancy of pyruvate as a metabolic substrate for monitoring enzymatic activity in vivo. This work provides a detailed description of the experimental setup and methods required for the study of enzymatic reactions, in particular the pyruvate-to-lactate conversion rate in presence of lactate dehydrogenase (LDH), by hyperpolarized NMR.

The sensitivity enhancement provided by dissolution dynamic nuclear polarization (DNP) enables following metabolic processes in real time by NMR and MRI. The characteristics and performances of a dedicated dissolution DNP setup designed for study enzymatic reactions are discussed.

Die Auflösung dynamische Kernpolarisation Besetzung für Echtzeit-enzymatische Reaktionsgeschwindigkeit Messungen von NMR

The main limitation of NMR-based investigations is low sensitivity. This prompts for long acquisition times, thus preventing real-time NMR measurements of ...

Chemie

High-pressure, High-temperature Deformation Experiment Using the New Generation Griggs-type Apparatus

In order to address geological processes at great depths, rock deformation should ideally be tested at high pressure (&#62; 0.5 GPa) and high temperature (&#62; 300 &#176;C). However, because of the low stress resolution of current solid-pressure-medium apparatuses, high-resolution measurements are today restricted to low-pressure deformation experiments in the gas-pressure-medium apparatus. A new generation of solid-medium piston-cylinder (&#34;Griggs-type&#34;) apparatus is here described. Able to perform high-pressure deformation experiments up to 5 GPa and designed to adapt an internal load cell, such a new apparatus offers the potential to establish a technological basis for high-pressure rheology. This paper provides video-based detailed documentation of the procedure (using the &#34;conventional&#34; solid-salt assembly) to perform high-pressure, high-temperature experiments with the newly designed Griggs-type apparatus. A representative result of a Carrara marble sample deformed at 700 &#176;C, 1.5 GPa and 10-5 s-1 with the new press is also given. The related stress-time curve illustrates all steps of a Griggs-type experiment, from increasing pressure and temperature to sample quenching when deformation is stopped. Together with future developments, the critical steps and limitations of the Griggs apparatus are then discussed.

Rock deformation needs to be quantified at high pressure. A description of the procedure to perform deformation experiments in a newly designed solid-medium Griggs-type apparatus is here given. This provides technological basis for future rheological studies at pressures up to 5 GPa.

Hochdruck- und Hochtemperatur-Verformung Experiment mit der neuen Generation Griggs-Typ Apparat

In order to address geological processes at great depths, rock deformation should ideally be tested at high pressure (&#62; 0.5 GPa) and high temperature ...

Umwelt

High Pressure Single Crystal Diffraction at PX^2

In this report we describe detailed procedures for carrying out single crystal X-ray diffraction experiments with a diamond anvil cell (DAC) at the GSECARS 13-BM-C beamline at the Advanced Photon Source. The DAC program at 13-BM-C is part of the Partnership for Extreme Xtallography (PX^2) project. BX-90 type DACs with conical-type diamond anvils and backing plates are recommended for these experiments. The sample chamber should be loaded with noble gas to maintain a hydrostatic pressure environment. The sample is aligned to the rotation center of the diffraction goniometer. The MARCCD area detector is calibrated with a powder diffraction pattern from LaB6. The sample diffraction peaks are analyzed with the ATREX software program, and are then indexed with the RSV software program. RSV is used to refine the UB matrix of the single crystal, and with this information and the peak prediction function, more diffraction peaks can be located. Representative single crystal diffraction data from an omphacite (Ca0.51Na0.48)(Mg0.44Al0.44Fe2+0.14Fe3+0.02)Si2O6 sample were collected. Analysis of the data gave a monoclinic lattice with P2/n space group at 0.35 GPa, and the lattice parameters were found to be: a = 9.496 &#177;0.006 &#197;, b = 8.761 &#177;0.004 &#197;, c = 5.248 &#177;0.001 &#197;, &#946; = 105.06 &#177;0.03&#186;, &#945; = &#947; = 90&#186;.

In this report, we describe detailed procedures for carrying out single crystal X-ray diffraction experiments with a diamond anvil cell at the GSECARS 13-BM-C beamline at the Advanced Photon Source. ATREX and RSV programs are used to analyze the data.

High Pressure Einkristalldiffraktometrie bei PX ^ 2

In this report we describe detailed procedures for carrying out single crystal X-ray diffraction experiments with a diamond anvil cell (DAC) at the ...

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

We demonstrate the use of two nuclear-based analytical methods that can follow the modifications of microstructural arrangement of iron-based metallic glasses (MGs). Despite their amorphous nature, the identification of hyperfine interactions unveils faint structural modifications. For this purpose, we have employed two techniques that utilize nuclear resonance among nuclear levels of a stable 57Fe isotope, namely M&#246;ssbauer spectrometry and nuclear forward scattering (NFS) of synchrotron radiation. The effects of heat treatment upon (Fe2.85Co1)77Mo8Cu1B14 MG are discussed using the results of ex situ and in situ experiments, respectively. As both methods are sensitive to hyperfine interactions, information on structural arrangement as well as on magnetic microstructure is readily available. M&#246;ssbauer spectrometry performed ex situ describes how the structural arrangement and magnetic microstructure appears at room temperature after the annealing under certain conditions (temperature, time), and thus this technique inspects steady states. On the other hand, NFS data are recorded in situ during dynamically changing temperature and NFS examines transient states. The use of both techniques provides complementary information. In general, they can be applied to any suitable system in which it is important to know its steady state but also transient states.

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

Here, we present a protocol to describe ex situ and in situ investigations of structural transformations in metallic glasses. We employed nuclear-based analytical methods which inspect hyperfine interactions. We demonstrate the applicability of M&#246;ssbauer spectrometry and nuclear forward scattering of synchrotron radiation during temperature-driven experiments.

Methoden der Ex-Situ und In Situ Untersuchungen zu strukturellen Veränderungen: der Fall der Kristallisation von metallischen Gläsern

We demonstrate the use of two nuclear-based analytical methods that can follow the modifications of microstructural arrangement of iron-based metallic ...

High-Pressure NMR Experiments for Detecting Protein Low-Lying Conformational States

High-pressure is a well-known perturbation method that can be used to destabilize globular proteins and dissociate protein complexes in a reversible manner. Hydrostatic pressure drives thermodynamical equilibria toward the state(s) with the lower molar volume. Increasing pressure offers, therefore, the opportunities to finely tune the stability of globular proteins and the oligomerization equilibria of protein complexes. High-pressure NMR experiments allow a detailed characterization of the factors governing the stability of globular proteins, their folding mechanisms, and oligomerization mechanisms by combining the fine stability tuning ability of pressure perturbation and the site resolution offered by solution NMR spectroscopy. Here we present a protocol to probe the local folding stability of a protein via a set of 2D 1H-15N experiments recorded from 1 bar to 2.5 kbar. The steps required for the acquisition and analysis of such experiments are illustrated with data acquired on the RRM2 domain of hnRNPA1.

We provide a detailed description of the steps required to assemble a high-pressure cell, set up and record high-pressure NMR experiments, and finally analyze both peak intensity and chemical shift changes under pressure. These experiments can provide valuable insights into the folding pathways and structural stability of proteins.

Hochdruck-NMR-Experimente zum Nachweis von proteinarmen Konformationszuständen

High-pressure is a well-known perturbation method that can be used to destabilize globular proteins and dissociate protein complexes in a reversible ...

Biochemie

An Externally-Heated Diamond Anvil Cell for Synthesis and Single-Crystal Elasticity Determination of Ice-VII at High Pressure-Temperature Conditions

The externally-heated diamond anvil cell (EHDAC) can be used to generate simultaneously high-pressure and high-temperature conditions found in Earth&#8217;s and planetary interiors. Here we describe the design and fabrication of the EHDAC assemblies and accessories, including ring resistive heaters, thermal and electrical insulating layers, thermocouple placement, as well as the experimental protocol for preparing the EHDAC using these parts. The EHDAC can be routinely used to generate megabar pressures and up to 900 K temperatures in open air, and potentially higher temperatures up to ~1200 K with a protective atmosphere (i.e., Ar mixed with 1% H2). Compared with a laser-heating method for reaching temperatures typically &#62;1100 K, external heating can be easily implemented and provide a more stable temperature at &#8804;900 K and less temperature gradients to the sample. We showcased the application of the EHDAC for synthesis of single crystal ice-VII and studied its single-crystal elastic properties using synchrotron-based X-ray diffraction and Brillouin scattering at simultaneously high-pressure high-temperature conditions.

This work focuses on the standard protocol for preparing the externally-heated diamond anvil cell (EHDAC) for generating high-pressure and high-temperature (HPHT) conditions. The EHDAC is employed to investigate materials in Earth and planetary interiors under extreme conditions, which can be also used in solid state physics and chemistry studies.

Eine extern beheizte Diamant-Ambosszelle zur Synthese und Einzelkristallelastizitätsbestimmung von Eis-VII bei Hochdruck-Temperaturbedingungen

The externally-heated diamond anvil cell (EHDAC) can be used to generate simultaneously high-pressure and high-temperature conditions found in ...

High-Temperature and High-Pressure In situ Magic Angle Spinning Nuclear Magnetic Resonance Spectroscopy

Nuclear magnetic resonance (NMR) spectroscopy represents an important technique to understand the structure and bonding environments of molecules. There exists a drive to characterize materials under conditions relevant to the chemical process of interest. To address this, in situ high-temperature, high-pressure MAS NMR methods have been developed to enable the observation of chemical interactions over a range of pressures (vacuum to several hundred bar) and temperatures (well below 0 &#176;C to 250 &#176;C). Further, the chemical identity of the samples can be comprised of solids, liquids, and gases or mixtures of the three. The method incorporates all-zirconia NMR rotors (sample holder for MAS NMR) which can be sealed using a threaded cap to compress an O-ring. This rotor exhibits great chemical resistance, temperature compatibility, low NMR background, and can withstand high pressures. These combined factors enable it to be utilized in a wide range of system combinations, which in turn permit its use in diverse fields as carbon sequestration, catalysis, material science, geochemistry, and biology. The flexibility of this technique makes it an attractive option for scientists from numerous disciplines.

The molecular structures and dynamics of solids, liquids, gases, and mixtures are of critical interest to diverse scientific fields. High-temperature, high-pressure in situ MAS NMR enables detection of the chemical environment of constituents in mixed phase systems under tightly controlled chemical environments.

Hochtemperatur- und Hochdruck-In-situ-Magic Angle Spinning Nuclear Magnetic Resonance Spectroscopy

Nuclear magnetic resonance (NMR) spectroscopy represents an important technique to understand the structure and bonding environments of molecules. There ...