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. Montaj ve 6H-SiC Büyük Koni Boehler-tipi Anvils Hizalamalı <ol><li> Montaj araçları piston ve xy plaka düzeltmek ve oturma alanında Boehler-tipi anvils yerleştirin. </li><li> Tabii her örs sırt plakaları sıkıca oturur olun. </li><li> (Örneğin, Stycast 1266), kendi koltuk hem anvils tutkal, epoksi reçine kullanma. Oda sıcaklığında 12 saat ya da 2 saat boyunca bir fırın içinde 65 ° C &#39;için tedavi. </li><li> Yeterli bir örs uyum için, arka plakaları hizalayın ve hem de örsün paralelliği izlemek için M1 set vidaları kullanın. Örsler paralel olmayan olduğu bulunmuştur ise, epoksi reçinesi çıkarın ve yeniden başlatma alanına 1.2. </li></ol> 2. Conta Hazırlık <ol><li> Tavlı Cu-Be bir çip içine matkap, 1 mm delik pirinç kılavuz pinlerinin (w% Cu 98, ağırlıkça% 2, 0.5 mm kalınlığında olun). </li><li> GUID&#39;deki olarak hizmet etmek üzere, örs boyunca dağıtılmış olan delikler üç tane 5 mm ve çapı 1 mm olmayan izole edilmiş bakır telden uzun parçalar kaydedinCu-Be conta e pimleri. </li><li> Kılavuz pimleri ve hücre gövdesi arasında uygun topraklama için kontrol edin. Tipik haliyle, yaklaşık 0.1 Ω bir DC direnci arzu edilir. Iletken gümüş küçük bir miktarda bir uygulama ile geliştirin. </li><li> Moisanit örs üzerine Cu-Be çip yerleştirin ve hücre kapatın. </li><li> Bir hidrolik pres kullanarak, en üst düzeyde çalışma istikrar için culet çapının yaklaşık 1/8 inci conta basınç. Bir mikrometre kaliper kullanılarak girinti gerçek kalınlığının izleyin. </li><li> Girintinin merkezinde uygun çapın (culet çapının ½) bir delik delin. </li><li> Önceden girintili conta haline iki kanal bölmek. Kanallar mikro-bobinin 18 mikron bakır tel karşılamak için yeterince derin olmalı. </li><li> Harden fırında 2 saat 3 için 617 K&#39;de hazırlanmış conta. </li></ol> 3. hazırlanması ve Mikro-bobinin Yükleme <ol><li> 1 mm bakır tel an bölgesinin bir parça kullanınPistonun boydan boya besleme geçirmektir d. Epoksi reçine ile bakır tel Fix ve adım 1.3 göre bunu tedavi. </li><li> Mikro-coil için istenen çapa sahip bir bız (malzemelerin listesini görmek) seçin ve dönebilen ayna çeneleri bir çift arasında bunu düzeltmek. </li><li> Tutkal diğer ucunu tutarken, çeneleri üzerine 18 mikron bakır telin bir ucunu (SCB dan eg, vernik ile, malzemelerin listesini görmek) ve tel tığ üzerine sarılmış şekilde ayna çene döndürün. </li><li> Mikro bobin istenilen geometrinin olduğunda, hem de tutkal üzerine telin diğer ucunu sabitlemek. </li><li> Sargılarının üst kısmında küçük bir miktarın uygulanmasıyla bobini sabitlemek için seyreltilmiş vernik. </li><li> Teflon bant kullanarak tığ dikkatlice bobini çıkarın. </li><li> Contanın kanalları, herhangi bir katkı maddesi, bir epoksi reçinesi (noktası 1.3) yerleştirin. </li><li> Numune odasının içine mikro-coil yerleştirin ve kanallar içine uçlarını sabitleyin. </li><li> Epox Curey reçine göre 1.3 adıma. </li><li> Sıcak tel mikro bobini ve bir kılavuz pimi diğer bir kurşun lehim. </li><li> Her kavşak üstüne bazı gümüş iletken macun ekleyin. Tipik Kür birkaç dakika sürer. </li><li> Epoksi reçinenin küçük bir miktarı ile, her iki kavşaklar Seal. </li><li> 1.3 aşamasına göre epoksi Cure. </li><li> Şimdi, her adımdan sonra bobinin DC direnci kontrol edin. </li><li> Mikro bobinindeki numuneyi. Gereksiz fiziksel temas bobini yok olabileceğini unutmayın. </li><li> Basınç kalibrasyon için numuneye ince öğütülmüş yakut toz ekleyin. </li><li> Son olarak, uygun bir basınç ortam maddesi ile numune haznesi sel. 9 GPa kadar neredeyse-hidrostatik koşulları sağlamak için parafin yağı kullanın. </li><li> Dikkatli bir şekilde hücre kapatın. </li></ol> 4. Uygulama ve Basınç İzleme <ol><li> İlk başta biraz M3 Allen gömme vidayı sıkın. </li><li> Basınçlandırma için bir mengene hücreyi düzeltmek. Şimdi, sıkınİki karşıt vida ikili. </li><li> Bir hücre tutucuya basınçlı hücre yerleştirin. </li><li> Lazer ışını, numune odasına ulaşır, böylece hücrenin pozisyonunu ayarlar. </li><li> Lazer ışını yakut tozu odaklanmak için ince ayar tablosunu kullanın. </li><li> İlgili spektrometre yazılımını kullanarak yakut fotolüminesans spektrumunu izleyin. </li><li> Yakut R1 ve R2 hatlarının gözlenen tayf kayması örnek boşluğunda gerçek basıncı ayıklayın. </li><li> NMR ölçümleri çalıştırılmadan önce en az 12 saat boyunca basınçlı hücre dengelenmesi. </li></ol> 5. Sahne NMR Deneyleri <ol><li> Tipik NMR sonda üzerine basınç hücresi monte edin. Mekanik atölye uygun hücre taşıyıcıların imalatı. </li><li> Sondaya sıcak tel lehim. Hücre ve sonda arasında uygun elektrik teması kontrol edin. </li><li> Şimdi, standart NMR deneyleri gerçekleştirmek. Mikro-bobin ver olduğu gerçeğine dikkat çekmekuygulanan radyo frekansı gücüne karşı duyarlı y. </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.

Giga-Pascal basınçlarında NMR gerçekleştirmek için, yeni ve umut verici bir yöntem tarif edilmiştir. Bu yöntem nedeniyle mükemmel hassasiyet ve çözünürlük NMR deneyleri geniş bir çeşitli kapı açılır. Bununla birlikte, protokol bölümünde açıklanan çeşitli adımlar deney sonucu için çok önemlidir. Özellikle, mikro-coil hazırlanması ve Cu-Be conta onun sabitleme çok zordur ve deneyim gerektirir. Aşağıda bununla ilgili bazı önemli ipuçları tekniğin bir birinci uygulama başarılı...

Geçen yüzyılın başında, yüksek hidrostatik basınç altında yoğunlaştırılmış madde Percy BRIDGMAN damgasını deneylerde bu yana, yüksek basınç fizik alanı hızla 1 gelişmiştir. Ilgi çekici fenomenlerin çok sayıda çeşitli GPa 2 basınçlar altında meydana geldiği bilinmektedir. Buna ek olarak, yüksek basınç yoğun madde sistemlerin yanıtı bize elektronik zemin ve uyarılmış hal 3,4 hakkında çok şey öğretti. Ne yazık ki, Giga-Pascal basınçlarında Yoğun madde elektronik özelliklerinin incelenmesi için teknikler x-ray ya da yolunu 5 önde gelen DC direnç ölçümleri ile nadirdir. Özellikle, elektron spin (ESR), ve nükleer manyetik rezonans (NMR) deneyleri, elektronik ya da nükleer Manyetik anlar üzerinde bir algılama gelen sinyali almak için gereken tipik bir yüksek basınçlı örs hücrelerde uygulanması neredeyse imkânsız olacağı kesindir küçük bir volume örs ve bir sızdırmaz contası tarafından konulan. Çeşitli gruplar, karmaşık düzenlemeler kullanarak bu sorunu çözmek için çalıştık, örneğin, iki bölünmüş çift radyo frekans (RF) bobinler örsün 6 yanları boyunca yara, bir tek veya çift döngü saç iğnesi rezonatörünü 7,8; . 1 gibi çekirdekler γ - ya da bir RF bobin tarafından 9, Şekil 1, bir çift olarak bölünmüş renyum conta Ne yazık ki, bu yaklaşım hala büyük için deneysel uygulamalar sınırlayan düşük bir sinyal-gürültü oranı (SNR) muzdarip H 10. 15 - İlgilenen okuyucu diğer yüksek basınçlı rezonans tank devresi deneyleri 11 ifade edilebilir. Pravica ve Silvera 16 rapor hidrojen orto-para dönüşüm incelenmiştir 12.8 GPa, NMR ile bir örs hücrede elde edilen en yüksek basınç. NMR uygulayarak büyük bir ilgi ilekuantum katıların özelliklerini incelemek için, bizim grup da yüksek basınçlar mevcut NMR olan ilgi oldu. Nihayet, 2009 yılında bir rezonansa radyo frekansı (RF) mikro-bobin örnek 17 çevreleyen yüksek basınç boşluğuna doğrudan yerleştirilir eğer yüksek hassasiyetli örs hücre NMR gerçekten mümkün olduğunu gösterdi olabilir. Bu tür bir yaklaşımda, NMR hassasiyeti, toz numuneleri üzerinde 17 A, NMR, örneğin daha da zor bir NMR deneyleri mümkün kılan, (RF bobini faktörü doldurulmasında çoğunlukla dramatik artışa bağlı olarak), birkaç büyüklük geliştirilir 7&#39;ye kadar 18 GPa yüksek-sıcaklık süper-iletken. Bu malzemeler içinde büyük ölçüde süper-iletkenlik basınç uygulanması ile amplifiye edilebilir ve bu süreçlere ilişkin temel fikir söz yerel elektronik sonda ile bu işlemi takip etmek mümkündür. Ne olduğunu, yüksek basınç altında NMR ve güç için bir başka örnek ortaya Believed rutin deneyler referans olması: - Basit alüminyum metal gelen yeni örs hücre NMR test etmek için, en iyi bilinen malzemelerin bir ölçülmüştür. Basınç arttıkça, tek bir serbest elektron sistemi için beklediğiniz gelen NMR kayması beklenmedik bir sapma tespit edildi. Daha yüksek basınç altında da, deney tekrarlandı, yeni sonuçlar gerçekten de güvenilir olduğunu göstermektedir. Işlem gücü düşük olduğunda Nihayet, bant yapısı hesaplamaları ile daha sonra, sonuçları yıl önce hesaplamalar tarafından tespit edilemeyen alüminyum Fermi yüzeyinin, bir topolojik geçiş tezahürü olduğu tespit edilmiştir. Ortam koşullarına bulguların ekstrapolasyonunda hemen hemen her yerde kullanılır bu metalin özellikleri bu özel elektronik durumun etkili olduğunu gösterdi. Farklı uygulamalar bir dizi takip etmek için özel olarak tasarlanmış örs hücreleri (önceki hücreleri Cavend ithal edilmiştiNMR sonradan ish Laboratuar ve) geliştirilmiştir. Şu anda, ikinci ev yapımı taşıyıcı 800 um culet 6H-SiC örsün çifti kullanılarak 25 GPa kadar basınç ulaşma kabiliyetine sahiptir. NMR deneyleri başarıyla bugüne kadar, 10.1 GPa kadar yapılmıştır. Bu yeni hücre NMR performansı 19 çok iyi olduğu gösterilmiştir. Ana bileşen Titanyum-Alüminyum (6) -vanadyum (4) yaklaşık 800 akma mukavemeti MPa 20 sağlayan bir ekstra düşük interstisyel düzeyde (sınıf 23), ile. Sayesinde manyetik olmayan özellikleri (manyetik duyarlılık χ yaklaşık 5 ppm) o örs hücre şasi için yeterli bir malzeme olduğundan. Tanıttı hücreler (tüm ev inşa örs hücre tasarımları bir bakış için bakınız Şekil 2) genel ölçüler normal standart delik NMR mıknatıslar içine sığacak kadar küçük. Yüksekliği sadece 20 mm ve 17 mm küçük tasarım, LAC-TM1, aynı zamanda tipik bir küçük kalibreli soğuk mıknatıslar (30 mm delik çapı) uyar. LYazarlar tasarlanmış en son şasi AC TM2, (iç basınç düzgün bir kontrolü için bağlanmış mavi baskı sağlayan basınç tahrik mekanizması olarak (ki bu hücre şasi ile aynı alaşımdan yapılmış) dört adet M4 Allen havşa civatalar kullanır ek bölüm). Tipik olarak, elmas örsler 100 GPa üzerinde en yüksek basınçlar oluşturmak için kullanılır. Xu Mao 21-23 moisanit örsler yaklaşık 60 GPa basınçlara kadar, yüksek basınçlı araştırma maliyetli bir alternatif temin olduğunu göstermiştir. Bu nedenle moisanit örsler katılan GPa NMR yaklaşım kullanılmıştır. En iyi sonuçlar Charles &amp; Colvard bir örs bölümünden özelleştirilmiş büyük koni 6H-SiC örs ile elde edilmiştir. Bu hücreler sayesinde, 10.1 GPa kadar basınçlar için 800 um culet örsün kullanımı çok iyi NMR duyarlılık ile sonuçlandığı bulunmuştur. Karşılaştırma için, Lee ve ark. 1H NM 1 bir SNR raporTanıtılan mikro bobin yaklaşımın SNR hatta biraz daha düşük manyetik alan, kendi hacminin 1/7 için 25 değerini gösterirken musluk suyu R,. Modern malzeme fiziği ve kimyası heyecan verici yeni bir bakış açısı söz birçok uygulama takip edebilirsiniz yüksek hassasiyetli örs hücre NMR birine bu yeni yaklaşım ile. Bir küçük culet boyutlarını talep çok daha yüksek basınçlar ilgilenen Ancak, her zaman olduğu gibi, hassasiyet ve çözünürlük sonuçta, özellikle, NMR uygulamasını sınırlamak. Sonra, bir daha küçük RF bobinleri ile hücre tasarımı optimize değil, aynı zamanda nükleer kutuplaşmayı arttırmak için yöntemler düşünmek sadece vardır.

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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.

Şekil 3, tipik bir NMR sonda üzerine tamamen monte edilmiş basınçlı hücre, kablo ve montaj gibi gösterir. Aşağıda, çeşitli deneyler faydaları ve tanıttı tekniğinin sınırları hakkında geniş bir bakış toplamak için okuyucunun hangi gözden geçirilecektir. <img alt="Şekil 1" src="/files/ftp_upload/52243/52243fig1highres.jpg" /> Şekil yüksek basınç NMR 1. Çeşitli Yaklaşımlar: örs kana...

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.

Aşırı Koşullarında Yoğun Madde Elektronik ve Kimyasal Özellikler Probing için Yeni Bir Aracı: Giga Pascal Baskılara yüksek-Hassasiyet Nükleer Manyetik Rezonans

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

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Principles of Nuclear Magnetic Resonance

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11.5K Görüntüleme.  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.

Video: 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.

NMR ve MRG Uygulamaları için Hyperpolarized Xenon

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

Mühendislik

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.

Aşırı basınç ve Sıcaklıklarda sentezi ve mikrodifraksiyon

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.

Planetary İçişleri Farklılaşma Simülasyon Laboratuvarı Süreçleri

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.

NMR ile Gerçek zamanlı enzimatik Reaksiyon Hızı Ölçümleri için çözünme Dinamik Nükleer Polarizasyon Aletler

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

Kimya

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.

Yeni nesil Griggs tipi cihazlar kullanarak yüksek basınç, yüksek sıcaklık deformasyon deney

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 ...

Çevre

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.

Yüksek Basınçlı PX de Tek Kristal Kırınımı ^ 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.

Ex Situ ve yapısal dönüşümleri in Situ soruşturma yöntemleri: Metalik gözlük kristalleşme olgusu

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.

Protein Düşük Yatan Konformasyon durumlarını tespit etmek için Yüksek Basınçlı NMR Deneyleri

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

Biyokimya

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.

Yüksek Basınç-Sıcaklık Koşullarında Buz-VII Sentezi ve Tek Kristal Elastikiyet Tayini için Harici Isıtılmış Elmas Örs Hücresi

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.

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