Name: spark plasma sintering apparatus used for the formation of strontium titanate bicrystals
Uploaded: 2017-02-09T15:00:00
Description: Watch this Scientific Journal Video about Spark Plasma Sintering Apparatus Used for the Formation of Strontium Titanate Bicrystals at JoVE.com

LH erkjenner takknemlig økonomisk støtte av en US National Science Foundation Graduate Research Fellowship i henhold Grant No. 1148897. Elektronmikroskopi karakterisering og SPS behandling ved UC Davis ble finansielt støttet av en University of California Laboratory Fee award (# 12-LR-238313). Arbeid på Molecular Foundry ble støttet av Office of Science, Office of Basic Energy Sciences, av US Department of Energy under kontrakt DE-AC02-05CH11231.

1. Prøvepreparering av én krystall strontium titanate MERK: Single krystall STO leveres med en (100) overflate polert til en speil finish. <ol><li> § STO til 5x5 mm 2 brikker bruker diamantwire så. </li><li> Ultralyd rene prøver på 50-60 Hz fortløpende i bad av aceton, isopropanol, og metanol for femten minutter hver. </li><li> Fjern STO fra metanol-bad til umiddelbart å sette på en varm plate holdt ved en temperatur på 200 ° C. Oppvarming av prøven etter rengjøring...

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	<li>Munir, Z. A., Anselmi-Tamburini, U., Ohyanagi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+electric+field+and+pressure+on+the+synthesis+and+consolidation+of+materials:+A+review+of+the+spark+plasma+sintering+method.">The effect of electric field and pressure on the synthesis and consolidation of materials: A review of the spark plasma sintering method.</a> J. Mater. Sci. 41 (3), 763-777 (2006).</li><li>Chen, W., Anselmi-Tamburini, U., Garay, J. E., Groza, J. R., Munir, Z. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fundamental+investigations+on+the+spark+plasma+sintering/synthesis+process:+I.+Effect+of+dc+pulsing+on+reactivity.">Fundamental investigations on the spark plasma sintering/synthesis process: I. Effect of dc pulsing on reactivity.</a> Mater. Sci. Eng. A. 394 (1-2), 132-138 (2005).</li><li>Holland, T. B., Anselmi-Tamburini, U., Mukherjee, A. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electric+fields+and+the+future+of+scalability+in+spark+plasma+sintering.">Electric fields and the future of scalability in spark plasma sintering.</a> Scr. Mater. 69 (2), 117-121 (2013).</li><li>Wan, J., Duan, R., Mukherjee, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spark+plasma+sintering+of+silicon+nitride/silicon+carbide+nanocomposites+with+reduced+additive+amounts.">Spark plasma sintering of silicon nitride/silicon carbide nanocomposites with reduced additive amounts.</a> Scr. Mater. 53 (6), 663-667 (2005).</li><li>Carney, C. M., Mogilvesky, P., Parthasarathy, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oxidation+Behavior+of+Zirconium+Diboride+Silicon+Carbide+Produced+by+the+Spark+Plasma+Sintering+Method.">Oxidation Behavior of Zirconium Diboride Silicon Carbide Produced by the Spark Plasma Sintering Method.</a> J. Amer. Ceram. Soc. 92 (9), 2046-2052 (2009).</li><li>Dupeux, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Production+of+Oriented+Two-Phase+Bicrystals+by+Diffusion+Bonding+Technique.">Production of Oriented Two-Phase Bicrystals by Diffusion Bonding Technique.</a> J. Cryst. Growth. 66, 169-178 (1984).</li><li>Castro, R., van Benthem, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Sintering: mechanisms of convention nanodensification and field assisted processes. 35, (2012).</li><li>Byeon, S. C., Hong, K. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electric+field+assisted+bonding+of+ceramics.">Electric field assisted bonding of ceramics.</a> Mater. Sci. Eng. A. 287 (2), 159-170 (2000).</li><li>Wang, J., Conrad, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Contribution+of+the+space+charge+to+the+grain+boundary+energy+in+yttria-stabilized+zirconia.">Contribution of the space charge to the grain boundary energy in yttria-stabilized zirconia.</a> J. Mater. Sci. 49 (17), 6074-6080 (2014).</li><li>Fujimoto, M., Kingery, W. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microstructures+of+SrTiO3+Internal+Boundry+Layer+Capacitors+During+and+After+Processing+and+Resultant+Electrical+Properties.">Microstructures of SrTiO3 Internal Boundry Layer Capacitors During and After Processing and Resultant Electrical Properties.</a> J. Amer. Ceram. Soc. 68 (4), 169-173 (1985).</li><li>Mitsuma, 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=Structures+of+a+&#931;+=+9,+[110]/{221}+symmetrical+tilt+grain+boundary+in+SrTiO3.">Structures of a &#931; = 9, [110]/{221} symmetrical tilt grain boundary in SrTiO3.</a> Journal of Materials Science. 46 (12), 4162-4168 (2011).</li><li>Ikuhara, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Grain+Boundary+and+Interface+Structures+in+Ceramics.">Grain Boundary and Interface Structures in Ceramics.</a> J. Ceram. Soc. Jpn. 109 (7), S110-S120 (2001).</li><li>Hutt, S., Kienzle, O., Ernst, F., Ruhle, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Processing+and+Structure+of+Grain+boundaries+in+Strontium+Titanate.">Processing and Structure of Grain boundaries in Strontium Titanate.</a> Z. Metallkd. 92 (2), 105-109 (2001).</li><li>Takahisa, Y., Ikuhara, Y., Sakuma, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current-voltage+characteristics+across+45&#9702;+symmetric+tilt+boundary+in+highly+donor-doped+SrTiO3+bicrystal.">Current-voltage characteristics across 45&#9702; symmetric tilt boundary in highly donor-doped SrTiO3 bicrystal.</a> J. Mater. Sci. Lett. 20, 1827-1829 (2001).</li><li>Hill, A., Wallach, E. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modelling+Solid+State+Diffusion+Bonding.">Modelling Solid State Diffusion Bonding.</a> Acta Metall. 37 (9), 2425-2437 (1989).</li><li>Sato, 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=Non-linear+current-voltage+characteristics+related+to+native+defects+in+SrTiO3+and+ZnO+bicrystals.">Non-linear current-voltage characteristics related to native defects in SrTiO3 and ZnO bicrystals.</a> Sci. Technol. Adv. Mater. 4 (6), 605-611 (2003).</li><li>Hirose, S., Nishimura, H., Niimi, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Resistance+switching+effect+in+Nb-doped+SrTiO[sub+3]+(100)+bicrystal+with+(100)+&#8764;45&#176;+twist+boundary.">Resistance switching effect in Nb-doped SrTiO[sub 3] (100) bicrystal with (100) &#8764;45&#176; twist boundary.</a> J. App. Phys. 106 (4), 043711-043716 (2009).</li><li>Hutt, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Doctoral Thesis. , (2002).</li><li>Brunner, D., Taeri-Baghbadrani, S., Sigle, W., Ruhle, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Suprising+Results+of+a+Studay+on+the+Plasticity+in+Strontium+Titanate.">Suprising Results of a Studay on the Plasticity in Strontium Titanate.</a> J. Amer. Ceram. Soc. 84 (5), 1161-1163 (2001).</li><li>Gumbsch, P., Taeri-Baghbadrani, S., Brunner, D., Sigle, W., Ruhle, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plasticity+and+an+inverse+brittle-to-ductile+transition+in+strontium+titanate.">Plasticity and an inverse brittle-to-ductile transition in strontium titanate.</a> Phys. Rev. Lett. 87 (8), 085501-085504 (2001).</li><li>Taeri, S., Brunner, D., Sigle, W., Ruhle, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deformation+Behavior+of+Strontium+Titanate+between+Room+Temperature+and+1800K+under+Ambient+Pressure.">Deformation Behavior of Strontium Titanate between Room Temperature and 1800K under Ambient Pressure.</a> Z. Metallkd. 95, 433-446 (2004).</li><li>Takahashi, K., Ohtomo, A., Kawasaki, M., Koinuma, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advanced+Processing+and+Characterization+of+SrTiO3+Single+Crystals+and+Bicrystals+for+High+Tc+Superconducting+Film+Substrate.">Advanced Processing and Characterization of SrTiO3 Single Crystals and Bicrystals for High Tc Superconducting Film Substrate.</a> Mater. Sci. Eng. B. 41, 152-156 (1996).</li><li>Rhodes, W. H., Kingery, W. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dislocation+Dependence+of+Cationic+Diffusion+in+SrTiO3.">Dislocation Dependence of Cationic Diffusion in SrTiO3.</a> J. Amer. Ceram. Soc. 49 (10), 521-526 (1966).</li><li>Yamamoto, T., Hayashi, K., Ikuhara, Y., Sakuma, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Grain+Boundary+Structure+and+Electrical+Properties+in+Nb-Doped+SrTiO&lt;sub&gt;3&lt;/sub&gt;+Bicrystals.">Grain Boundary Structure and Electrical Properties in Nb-Doped SrTiO&lt;sub&gt;3&lt;/sub&gt; Bicrystals.</a> Key Eng. Mater. 181-182, 225-230 (2000).</li><li>Fitting, L., Thiel, S., Schmehl, A., Mannhart, J., Muller, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Subtleties+in+ADF+imaging+and+spatially+resolved+EELS:+A+case+study+of+low-angle+twist+boundaries+in+SrTiO3.">Subtleties in ADF imaging and spatially resolved EELS: A case study of low-angle twist boundaries in SrTiO3.</a> Ultramicroscopy. 106 (11-12), 1053-1061 (2006).</li><li>Hughes, L. A., van Benthem, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Formation+of+SrTiO3+bicrystals+using+spark+plasma+sintering+techniques.">Formation of SrTiO3 bicrystals using spark plasma sintering techniques.</a> Scr. Mater. 118, 9-12 (2016).</li></ol>

Bindingen temperatur på 1200 ° C ble valgt for å maksimal diffusjon som små endringer i temperaturen kan i stor grad påvirke kinetikken for alle diffusjonsbinding mekanismer. En temperatur på 1200 ° C er utenfor den sprø-duktile overgangstemperaturområdet for STO. Men prøven gikk sprøbrudd ved denne temperatur. Den katastrofal svikt i STO bicrystal var ikke uventet som STO har ~ 0,5% duktilitet ved 1200 ° C. Dessuten ble prøven holdt ved et trykk på 140 MPa i hele oppvarmingsprosessen og STO overganger gje...

<html> Tennplasmasintring (SPS) er en teknikk der anvendelse av høy enakset trykk og pulserende likestrøm fører til hurtig fortetning av pulveret kompakterer 1. Denne teknikk fører også til en vellykket dannelse av sammensatte strukturer av forskjellige materialer, blant silisiumnitrid / silisiumkarbid, zirkoniumborid / silisiumkarbid, eller silisiumkarbid, med ingen ytterligere sintringshjelpemidler som kreves to, tre, fire, fem. Syntesen av disse sammensatte strukturer ved konvensjonelle varm-presse, var blitt utfordret i fortiden. Selv om anvendelse av et høyt enakset trykk og rask oppvarmingshastighet via SPS teknikk forbedrer konsolidering av pulver og kompositter, det fenomen som forårsaker denne forbedrede fortetting diskutert i litteraturen, 2, 3,class = &quot;xref&quot;&gt; 6, 7. Det eksisterer også bare begrenset informasjon angående påvirkning av elektriske felter på korngrensedannelse og de resulterende atomstruktur i korngrense kjerner 8, 9. Disse kjernestrukturer bestemme de funksjonelle egenskaper til SPS sintrede materialer, inkludert elektrisk nedbrytning av høyspente kondensatorer og den mekaniske styrke og seighet av keramiske oksider 10. Derfor forstå den grunnleggende korngrense struktur som en funksjon av SPS prosessparametere, slik som tilførte strøm, som er nødvendig for manipulering av et materiale totale fysiske egenskaper. En metode for å systematisk belyse de grunnleggende fysiske mekanismene som ligger til grunn SPS er dannelsen av spesifikke korn grensen strukturer, dvs. bicrystals. En bicrystal er skapt ved manipulering av to enkelt-krystaller, som deretter diffusion limt med spesifikke feilorientering vinkler 11. Denne metoden gir en kontrollert måte for å undersøke de grunnleggende korn grensen kjernestrukturer som en funksjon av prosessparametre, dopemiddelkonsentrasjon, og urenhet segregering 12, 13, 14. Diffusjonsbinding er avhengig av fire parametere: temperatur, tid, trykk, og binding atmosfære 15. Konvensjonell diffusjonsbinding av strontium titanat (SrTiO 3, STO) bicrystals oppstår vanligvis ved et trykk under 1 MPa, innenfor et temperaturområde på 1,400-1,500 ° C, og tidsskalaer i området fra 3 til 20 timer 13, 14, 16, 17. I denne studien er bonding i en SPS apparat oppnås ved betydelig lavere temperatur og tidsskalaer i comparison til konvensjonelle metoder. For polykrystallinske materialer, redusert temperatur og tidsskalaer via SPS betydelig begrenser kornvekst, og dermed gi en fordel kontroll over en materialets egenskaper gjennom manipulering av sin mikrostruktur. SPS apparat, for et 5 x 5 mm 2 prøve, utøver et trykk på minimum 140 MPa. Innenfor den konvensjonelle diffusjonsbinding temperaturområde, Hutt et al. rapportere momentant brudd i STO når bonding trykket overstiger 10 MPa 18. Men viser STO temperaturavhengig plastisitet atferd som indikerer pressetrykk kan overstige 10 MPa ved bestemte temperaturer. Over 1200 ° C og under 700 ° C, oppviser STO viss duktilitet, ved hvilket understreker er større enn 120 MPa kan påføres uten momentant brudd i prøven. I det mellomliggende temperaturområde på 700-1,200 ° C, er STO sprø og erfaringer momentant brudd på slokker som er større enn 10 MPa. Ved 800 ° C, har STO liten deformerbarhet før frakturering ved spenninger mindre enn 200 MPa 19, 20, 21. Derfor må bindetemperaturer for STO bicrystal formasjon via SPS anordningen velges i henhold til den plastisitet oppførselen til materialet.

<table border="0" cellpadding="0" cellspacing="0" width="1429">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:373px;">Strontium titanate single crystal (100)</td>
			<td style="width:187px;">MTI Corporation</td>
			<td style="width:427px;">STOa101005S1-JP</td>
			<td style="width:443px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:373px;">Buffered oxide etch, hyrofluoric acid 6:1</td>
			<td style="width:187px;">JT Baker</td>
			<td style="width:427px;">&#160;MBI 1178-03</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:373px;">Scanning electron microscope (SEM)</td>
			<td style="width:187px;">FEI</td>
			<td>Model: 430 NanoSEM</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">SPS apparatus&#160;</td>
			<td>Sumitomo Coal Mining Co</td>
			<td>Model: Dr. Sinter 5000 SPS Apparatus</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">High Temperature Furnace</td>
			<td>Thermolyne</td>
			<td>Model: 41600</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ultrasonic Cleaner</td>
			<td>Bransonic</td>
			<td>Model: 221</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:373px;">Mechanical polisher</td>
			<td style="width:187px;">Allied High Tech Products</td>
			<td>15-2100-TEM</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:373px;">Diamond lapping film</td>
			<td style="width:187px;">3M</td>
			<td>660XV&#160;</td>
			<td>1 um to 9 um Grit Size</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:373px;">Diamond lapping film</td>
			<td style="width:187px;">3M</td>
			<td style="width:427px;">661X</td>
			<td>0.5 um to 0.1 um Grit Size</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:373px;">Colloidal silica</td>
			<td style="width:187px;">Allied High Tech Products</td>
			<td>180-20000</td>
			<td>.05 um Grit Size</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:373px;">Sputter coater</td>
			<td style="width:187px;">QuorumTech</td>
			<td>Model: Q150RES</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Focused ion beam (FIB) instrument&#160;</td>
			<td style="width:187px;">FEI</td>
			<td>Model: Scios dual-beamed focused ion beam (FIB) instrument&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Nanomill TEM specimen preparation system</td>
			<td style="width:187px;">Fischione Instruments</td>
			<td>Model: 1040</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Transmission electron microscope (TEM)&#160;</td>
			<td style="width:187px;">JEOL</td>
			<td>Model: JEM2500 SE&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Scanning transmission electron microscope (STEM)</td>
			<td style="width:187px;">FEI</td>
			<td>Model: TEAM 0.5&#160;</td>
			<td></td>
		</tr>
	</tbody>
</table>

spark plasma sintering apparatus used for the formation of strontium titanate bicrystals

A spark plasma sintering apparatus was used as a novel method for diffusion bonding of two single crystals of strontium titanate to form bicrystals with one twist grain boundary. This apparatus utilizes high uniaxial pressure and a pulsed direct current for rapid consolidation of material. Diffusion bonding of strontium titanate bicrystals without fracture, in a spark plasma sintering apparatus, is possible at high pressures due to the unusual temperature dependent plasticity behavior of strontium titanate. We demonstrate a method for the successful formation of bicrystals at accelerated time scales and lower temperatures in a spark plasma sintering apparatus compared to bicrystals formed by conventional diffusion bonding parameters. Bond quality was verified by scanning electron microscopy. A clean and atomically abrupt interface containing no secondary phases was observed using transmission electron microscopy techniques. Local changes in bonding across the boundary was characterized by simultaneous scanning transmission electron microscopy and spatially resolved electron energy-loss spectroscopy.

Bonding temperatur, tid, og feilorientering vinkel var endret for å bestemme optimale parametre som behøves for størst mulig bundet grensesnitt brøkdel av STO bicrystal (tabell 1). Grensesnittet ble ansett &quot;limt&quot; når korn grensen var ikke synlig under SEM imaging (figur 2a). En &quot;non-limt &#39;grensesnitt ble utstilt når et mørkt bilde kontrast eller tomrom var til stede på grensen plassering (figur 2b). Mørkt bild...

Watch this Scientific Journal Video about Spark Plasma Sintering Apparatus Used for the Formation of Strontium Titanate Bicrystals at JoVE.com

Spark Plasma Sintering Apparatus Used for the Formation of Strontium Titanate Bicrystals

A viable technique for the formation of strontium titanate bicrystals at high pressure and fast heating rate via the spark plasma sintering apparatus is developed.

Spark Plasma Sintring apparatet som brukes for dannelsen av strontium titanate Bicrystals

A spark plasma sintering apparatus was used as a novel method for diffusion bonding of two single crystals of strontium titanate to form bicrystals with ...

The goal of this procedure is to form strontium titanate bicrystals using a Spark Plasma Sintering apparatus in order to create grain boundary structures with well defined misorientations as a function of processing parameters, such as high pressure and heating rate. We need to understand whether grain boundaries generated during SPS are different from those produced during more traditional ceramic processing techniques. This will then help us generate new ceramic materials with unprecedented properties.The main advantage of this technique is to form specific grain boundaries with well defined misorientations for the systematic understanding of microstructure formation during spark plasma sintering. To begin sample preparation, use a diamond wire saw to cut five millimeter by five millimeter pieces of a strontium titanate single crystal with a 1-0-0 plane surface polished to a mirror finish. Clean the samples with an ultrasonic cleaner in baths of acetone, isopropanol, and methanol for 15 minutes each at 50 to 60 Hertz.Heat a hot plate to 200 degrees Celsius during the cleaning. Upon completing the ultrasonic cleaning in methanol, immediately place the samples on the hot plate to dry. Etch the samples in a six to one solution of ammonium fluoride and 49%hydrofluoric acid for 10 minutes.Rinse the etched samples in deionized water and isopropanol in sequence. Dry the samples with filtered dry air. Discard any samples that developed a rainbow patina on the optically flat side.First, place a 30 millimeter circle of graphite paper on a 30 millimeter diameter graphite plunger. Then, stack two STO single crystal samples with their optically flat sides facing each other on the center of the paper covered plunger. Rotate the top single crystal around the 1-0-0 axis to the desired misorientation angle.Carefully slide a 30 millimeter diameter graphite die over the crystals and plunger. Insert another 30 millimeter circle of graphite paper and plunger into the die on top of the crystal stack. Place the assembly on the lower graphite spacer of the SPS apparatus.And then place the other graphite spacer on top of the assembly. Use the z-axis control buttons to bring the upper punch down to apply a three kilonewton uniaxial force to the assembly. Insert a K type thermocouple into the side of the graphite die to reach the sample.Set the chamber pressure to approximately 10 Pascal. Then on the instrument program control, set the bond temperature, time, and heating rates for the experiment. Select sinter conditions of a DC pulse of 12 seconds on, two seconds off, and then start the sintering program.Once the program ends, allow the sample to cool to 150 degrees Celsius. Transfer the gray black reduced sample to a high temperature furnace. Anneal the sample at 1200 degrees Celsius for 140 hours in air at ambient pressure to obtain the off-white oxidized bicrystal.Use a diamond wire saw to slice the bicrystal into five millimeter by one millimeter pieces. Polish the cross-sections with decreasing grit sizes of diamond lapping film until the scratches are uniform at the smallest grit size. Then start a two minute polish of the cross-sections with continuously poured colloidal silica and a matte cloth.15 seconds before polishing ends, switch from pouring colloidal silica to pouring DI water onto the platen. Immediately rinse the polish sample in DI water for one minute. Clean the polished sample in consecutive ultrasonic cleaning baths of acetone, isopropanol, and methanol for 15 minutes each.Immediately after cleaning, dry the sample on a hot plate at 200 degrees Celsius. Melt the clean sample polished side up on a sample stub coated with colloidal graphite. Sputter coat the sample surface with two to three nanometers of carbon.First, place the focused ion beam copper grid in consecutive ultrasonic cleaner baths of acetone and isopropanol for one hour. Then, plasma clean the copper grid for 10 minutes. Place the STO bicrystal sample and the clean copper grid in the FIB apparatus with the sample stage set at seven millimeters.In the FIB instrument software, identify a region of interest along the grain boundary. Navigate to patterning control and select the rectangle patterning tool with the CE depth surface application for electron beam deposition of carbon. Insert the carbon gas injection needle and deposit a 15 by two by two micrometers cubed protective layer of carbon over the region of interest.Then, retract the injection needle. Return to patterning control and choose the rectangle patterning tool with a W dep application for ion beam deposition of tungsten. Insert the tungsten gas injection needle and deposit a protective layer of tungsten of the same dimensions over the region of interest.Retract the injection needle. In patterning control, select the regular cross section patterning tool with the silicon application property. Mill a 22 by 27 by 15 micrometer cubed trench above the protected ROI and a 22 by 25 by 15 micrometer cubed trench below the ROI.Then, in patterning control, use the silicon clean cross section patterning tool to clean the trenched lamella surface. Next, use the silicon rectangle patterning tool to cut a two micrometer wide J pattern with two micrometer wide rectangles into the sample. Switch to the easy lift dialog box and set the micromanipulator to the park position.Lower the micromanipulator and weld the sample to the tip of the micromanipulator by tungsten deposition. Then, extend the J patten into a U pattern. Lift the lamella from the bulk sample and rotate the micromanipulator 180 degrees to set the grain boundary perpendicular to the ion beam.Tungsten welds with a lamella to the copper grid. Then, cut the micromanipulator free from the lamella using the rectangle patterning tool. Deposit a 15 by two by four micrometer cubed layer of carbon and a 15 by two by eight micrometer cubed layer of tungsten over the area of interest.Then, with the ion beam, thin the sample first to approximately 200 nanometers with a cleaning cross section pattern. And then, with a rectangle pattern, thin the sample to electron transparency. Remove the copper FIB grid from the FIB apparatus and place the grid onto a NanoMil sample holder.Then place the sample holder into the NanoMil apparatus. Using the NanoMil apparatus software, mil the sample at 500 electron volts for 10 minutes to remove amorphous damage caused by the FIB. Place the cleaned TEM sample in a sample holder and insert the sample and holder into the STEM.In the STEM software, use the capture tool to obtain an image of the sample grain boundary. Strontium titanate bicrystals were formed from single crystal pairs at various misorientation angles using a Spark Plasma Sintering apparatus. The interface was considered to be bonded wherever the grain boundary was not observable in SEM imaging.Areas of dark contrast in the images are either attributed to voids or colloidal graphite diffusion between the single crystals. The maximum bonded interface fraction was achieved with zero degrees of misorientation, a bonding temperature of 600 or 700 degrees Celsius, a bonding duration of 90 minutes, and an annealing time of 100 hours. Increasing the angle of misorientation to approximately 45 degrees necessitated a higher bonding temperature and a longer annealing time to achieve a 45%bonded interface.High resolution TEM and high angle annular dark field STEM show an atomically abrupt grain boundary with no observed second phases or intergranular film. Electron energy loss spectroscopy at the interface showed decreased crystal field splitting of the titanium L2 and L3 edges and decreased intensity in the oxygen K edge compared to the bulk crystal, suggesting a greater concentration of oxygen vacancies at the interface. Following the same procedure, we can also form doped grain boundaries using the SPS.This will help us to address whether the electric field will change grain boundary segregation. After watching this video, you should have a good understanding of how to form bicrystals with atomically abrupt interface structures using SPS. Don't forget that hydrofluoric acid can be extremely hazardous and precautions, such as personal protective wear, should be taken.

Research

JoVE Journal

Engineering

Investigation of Early Plasma Evolution Induced by Ultrashort Laser Pulses

Gransking av Tidlig Plasma Evolution indusert av Ultrakorte laser pulser

Early plasma is generated owing to high intensity laser irradiation of target and the subsequent target material ionization. Its dynamics plays a ...

Encapsulation and Permeability Characteristics of Plasma Polymerized Hollow Particles

Innkapsling og Permeabilitet Kjennetegn på Plasma polymerisert Hollow Partikler

In this protocol, core-shell nanostructures are synthesized by plasma enhanced chemical vapor deposition. We produce an amorphous barrier by plasma ...

Characterization of Recombination Effects in a Liquid Ionization Chamber Used for the Dosimetry of a Radiosurgical Accelerator

Karakterisering av Rekombinasjon Effects i en flytende Ionization Chamber Brukes for Dosimetri av en radiosurgical Accelerator

Most modern radiation therapy devices allow the use of very small fields, either through beamlets in Intensity-Modulated Radiation Therapy (IMRT) or via ...

Flame Experiments at the Advanced Light Source: New Insights into Soot Formation Processes

Flamme Eksperimenter ved Advanced Light Source: Ny innsikt i Soot Formasjon Prosesser

The following experimental protocols and the accompanying video are concerned with the flame experiments that are performed at the Chemical Dynamics ...

How to Ignite an Atmospheric Pressure Microwave Plasma Torch without Any Additional Igniters

Hvordan Ignite en Atmosfærisk trykk Mikrobølgeovn Plasma Torch uten noen ekstra Tennere

This movie shows how an atmospheric pressure plasma torch can be ignited by microwave power with no additional igniters. After ignition of the plasma, a ...

Capillary-based Centrifugal Microfluidic Device for Size-controllable Formation of Monodisperse Microdroplets

Kapillær-baserte Sentrifugal mikrofluid Enhet for Size-kontrollerbar Dannelse av monodisperse mikrodråper

Here, we demonstrate a simple method for the rapid production of size-controllable, monodisperse, W/O microdroplets using a capillary-based centrifugal ...

Applying X-ray Imaging Crystal Spectroscopy for Use as a High Temperature Plasma Diagnostic

Bruk av X-ray Imaging Crystal spektroskopi for bruk som en High Temperature Plasma Diagnostic

X-ray spectra provide a wealth of information on high temperature plasmas; for example electron temperature and density can be inferred from line ...

An Atmospheric Pressure Plasma Setup to Investigate the Reactive Species Formation

En Atmosfærisk trykk Plasma Setup for å etterforske Reaktiv artsdannelse

Non-thermal atmospheric pressure (&#39;cold&#39;) plasmas have received increased attention in recent years due to their significant biomedical potential. ...

In Situ Synthesis of Gold Nanoparticles without Aggregation in the Interlayer Space of Layered Titanate Transparent Films

In Situ Synthesis of Gold Nanoparticles without Aggregation in the Interlayer Space of Layered Titanate Transparent Films

I Situ Syntese av gull nanopartikler uten Aggregation i folien Space of Layered titanate transparente filmer

Combinations of metal oxide semiconductors and gold nanoparticles (AuNPs) have been investigated as new types of materials. The in situ synthesis of AuNPs ...