We thank&#160;Siheng Wang, Qinxia Wang, Jing Gao, Yingxin Liu for their help with the experiments. This research used resources of the Advanced Photon Source (APS), a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. GeoSoilEnviroCARS (Sector 13) is supported by NSF-Earth Sciences (EAR-1128799), and the Department of Energy, Geosciences (DE-FG02-94ER14466). The development of EHDAC was supported by Externally-heated Diamond Anvil Cell Experimentation (EH-DANCE) project to B. Chen under Education Outreach and Infrastructure Development (EOID) program&#160;from COMPRES under NSF Cooperative Agreement EAR-1606856. X. Lai acknowledges the support from the start-up funding of China University of Geosciences (Wuhan) (no.162301202618). B. Chen acknowledges the support from the U.S. National Science Foundation (NSF) (EAR-1555388 and EAR-1829273).&#160;&#160;J.S. Zhang acknowledges the support from the U.S. NSF (EAR-1664471, EAR-1646527 and EAR-1847707).

1. Ring heater preparation
<ol>
	<li>Fabricating the ring heater base
	<ol>
		<li>Fabricate the ring heater base by a computer numerical control (CNC) milling machine using pyrophyllite based on the designed 3D model. The dimensions of the heater are 22.30 mm in outer diameter (OD), 8.00 mm in inner diameter (ID) and 2.25 mm in thickness. Sinter the heater base in the furnace at 1523 K for &#62;20 hours.</li>
	</ol>
	</li>
	<li>Wiring
	<ol>
		<li>Cut Pt 10 wt% Rh wire (diameter: 0.01 inch) into 3 equal-length wires (ab...

<ol>
	<li>Shen, G., 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=Laser-heated+diamond+anvil+cell+technique:+double-sided+heating+with+multimode+Nd:+YAG+laser.">Laser-heated diamond anvil cell technique: double-sided heating with multimode Nd: YAG laser.</a> Computer. 1, 2 (1996).</li><li>Zhang, J. S., Bass, J. D., Zhu, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-crystal+Brillouin+spectroscopy+with+CO2+laser+heating+and+variable+q.">Single-crystal Brillouin spectroscopy with CO2 laser heating and variable q.</a> Review of Scientific Instruments. 86 (6), 063905 (2015).</li><li>Benedetti, L. R., Loubeyre, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temperature+gradients,+wavelength-dependent+emissivity,+and+accuracy+of+high+and+very-high+temperatures+measured+in+the+laser-heated+diamond+cell.">Temperature gradients, wavelength-dependent emissivity, and accuracy of high and very-high temperatures measured in the laser-heated diamond cell.</a> High Pressure Research. 24 (4), 423-445 (2004).</li><li>Goncharov, A. F., Crowhurst, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pulsed+laser+Raman+spectroscopy+in+the+laser-heated+diamond+anvil+cell.">Pulsed laser Raman spectroscopy in the laser-heated diamond anvil cell.</a> Review of Scientific Instruments. 76 (6), 063905 (2005).</li><li>Meng, Y., Hrubiak, R., Rod, E., Boehler, R., Shen, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+developments+in+laser-heated+diamond+anvil+cell+with+in+situ+synchrotron+x-ray+diffraction+at+High+Pressure+Collaborative+Access+Team.">New developments in laser-heated diamond anvil cell with in situ synchrotron x-ray diffraction at High Pressure Collaborative Access Team.</a> Review of Scientific Instruments. 86 (7), 072201 (2015).</li><li>Prakapenka, V., 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=Advanced+flat+top+laser+heating+system+for+high+pressure+research+at+GSECARS:+application+to+the+melting+behavior+of+germanium.">Advanced flat top laser heating system for high pressure research at GSECARS: application to the melting behavior of germanium.</a> High Pressure Research. 28 (3), 225-235 (2008).</li><li>Du, Z., Miyagi, L., Amulele, G., Lee, K. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+graphite+ring+heater+suitable+for+diamond-anvil+cells+to+1300+K.">Efficient graphite ring heater suitable for diamond-anvil cells to 1300 K.</a> Review of Scientific Instruments. 84 (2), 024502 (2013).</li><li>Bassett, W. A., Shen, A., Bucknum, M., Chou, I. M. <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+diamond+anvil+cell+for+hydrothermal+studies+to+2.5+GPa+and+from-+190+to+1200&#176;+C.">A new diamond anvil cell for hydrothermal studies to 2.5 GPa and from- 190 to 1200&#176; C.</a> Review of Scientific Instruments. 64 (8), 2340-2345 (1993).</li><li>Kantor, I., 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=BX90:+A+new+diamond+anvil+cell+design+for+X-ray+diffraction+and+optical+measurements.">BX90: A new diamond anvil cell design for X-ray diffraction and optical measurements.</a> Review of Scientific Instruments. 83 (12), 125102 (2012).</li><li>Dubrovinsky, L., 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=Stability+of+ferropericlase+in+the+lower+mantle.">Stability of ferropericlase in the lower mantle.</a> Science. 289 (5478), 430-432 (2000).</li><li>Komabayashi, T., Hirose, K., Sata, N., Ohishi, Y., Dubrovinsky, L. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phase+transition+in+CaSiO3+perovskite.">Phase transition in CaSiO3 perovskite.</a> Earth and Planetary Science Letters. 260 (3-4), 564-569 (2007).</li><li>Datchi, F., Loubeyre, P., LeToullec, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extended+and+accurate+determination+of+the+melting+curves+of+argon,+helium,+ice+(H+2+O),+and+hydrogen+(H+2).">Extended and accurate determination of the melting curves of argon, helium, ice (H 2 O), and hydrogen (H 2).</a> Physical Review B. 61 (10), 6535 (2000).</li><li>Lai, X., 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=The+high-pressure+anisotropic+thermoelastic+properties+of+a+potential+inner+core+carbon-bearing+phase,+Fe7C3,+by+single-crystal+X-ray+diffraction.">The high-pressure anisotropic thermoelastic properties of a potential inner core carbon-bearing phase, Fe7C3, by single-crystal X-ray diffraction.</a> American Mineralogist. 103 (10), 1568-1574 (2018).</li><li>Yang, J., Mao, Z., Lin, J. F., Prakapenka, V. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-crystal+elasticity+of+the+deep-mantle+magnesite+at+high+pressure+and+temperature.">Single-crystal elasticity of the deep-mantle magnesite at high pressure and temperature.</a> Earth and Planetary Science Letters. 392, 292-299 (2014).</li><li>Zhang, D., 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+single+crystal+diffraction+at+PX^+2.">High pressure single crystal diffraction at PX^ 2.</a> Journal of Visualized Experiments. (119), e54660 (2017).</li><li>Sinogeikin, S., 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=Brillouin+spectrometer+interfaced+with+synchrotron+radiation+for+simultaneous+X-ray+density+and+acoustic+velocity+measurements.">Brillouin spectrometer interfaced with synchrotron radiation for simultaneous X-ray density and acoustic velocity measurements.</a> Review of Scientific Instruments. 77 (10), 103905 (2006).</li><li>Dubrovinskaia, N., Dubrovinsky, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whole-cell+heater+for+the+diamond+anvil+cell.">Whole-cell heater for the diamond anvil cell.</a> Review of Scientific Instruments. 74 (7), 3433-3437 (2003).</li><li>Fan, D., 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=A+simple+external+resistance+heating+diamond+anvil+cell+and+its+application+for+synchrotron+radiation+X-ray+diffraction.">A simple external resistance heating diamond anvil cell and its application for synchrotron radiation X-ray diffraction.</a> Review of Scientific Instruments. 81 (5), 053903 (2010).</li><li>Jenei, Z., Cynn, H., Visbeck, K., Evans, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-temperature+experiments+using+a+resistively+heated+high-pressure+membrane+diamond+anvil+cell.">High-temperature experiments using a resistively heated high-pressure membrane diamond anvil cell.</a> Review of Scientific Instruments. 84 (9), 095114 (2013).</li><li>Shinoda, K., Noguchi, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+induction+heating+diamond+anvil+cell+for+high+pressure+and+temperature+micro-Raman+spectroscopic+measurements.">An induction heating diamond anvil cell for high pressure and temperature micro-Raman spectroscopic measurements.</a> Review of Scientific Instruments. 79 (1), 015101 (2008).</li><li>Zha, C. S., Mao, H. -. k., Hemley, R. J., Duffy, T. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+progress+in+high-pressure+Brillouin+scattering:+olivine+and+ice.">Recent progress in high-pressure Brillouin scattering: olivine and ice.</a> The Review of High Pressure Science and Technology. 7, 739-741 (1998).</li><li>Zhang, J. S., Hao, M., Ren, Z., Chen, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+extreme+acoustic+anisotropy+and+fast+sound+velocities+of+cubic+high-pressure+ice+polymorphs+at+Mbar+pressure.">The extreme acoustic anisotropy and fast sound velocities of cubic high-pressure ice polymorphs at Mbar pressure.</a> Applied Physics Letters. 114 (19), 191903 (2019).</li></ol>

The authors declare no conflict of interest.

In this work, we described the protocol of preparing the EHDAC for high pressure research. The cell assemblies including a micro-heater and thermal and electrical insulating layers. Previously, there are multiple designs of resistive heaters for different types of DACs or experimental configurations7,17,18,19,20. Most of the heaters are machined by individual ...

The diamond anvil cell (DAC) is one of the most important tools for high pressure research. Coupled with synchrotron-based and conventional analytical methods, it has been widely used to study properties of planetary materials up to multi-megabar pressures and at wide ranges of temperatures. Most planetary interiors are under both high-pressure and high-temperature (HPHT) conditions. It is thus essential to heat the compressed samples in a DAC at high pressures in situ to study the physics and chemistry of planetary interiors. High temperatures are not only required for the investigations of phase and melting relationships and thermodynamic properties of planetary materials, but also help mitigate pressure gradient, promote phase transitions and chemical reactions, and expedite diffusion and recrystallization. Two methods are typically utilized to heat the samples in DACs: laser-heating and internal/external resistive heating methods.
The laser-heated DAC technique has been employed for high-pressure materials science and mineral physics research of planetary interiors1,2. Although increasing number of laboratories have access to the technique, it usually requires significant development and maintenance effort. The laser heating technique has been used to achieve temperatures as high as 7000 K3. However, long-duration stable heating as well as temperature measurement in laser-heating experiments have been a persistent issue. The temperature during laser heating usually fluctuates but can be mitigated by feed-back coupling between thermal emission and laser power. More challenging is controlling and determining the temperature for assembly of multiple phases of different laser absorbance. The temperature also has a considerably large gradient and uncertainties (hundreds of K), although recent technical development effort has been used to mitigate this issue4,5,6. Temperature gradients in the heated sample area sometimes may further introduce chemical heterogeneities caused by diffusion, re-partitioning or partial melting. In addition, temperatures less than 1100 K typically could not be measured precisely without customized detectors with high sensitivity in the infrared wavelength range.
The EHDAC uses resistive wires or foils around the gasket/seat to heat the entire sample chamber, which provides the ability of heating the sample to ~900 K without a protective atmosphere (such as Ar/H2 gas) and to ~1300 K with a protective atmosphere7. The oxidation and graphitization of diamonds at higher temperatures limit the highest achievable temperatures using this method. Although the temperature range is limited compared with laser-heating, it provides more stable heating for a long duration and a smaller temperature gradient8, and is well suited to be coupled with various detection and diagnostic methods, including optical microscope, X-ray diffraction (XRD), Raman spectroscopy, Brillouin spectroscopy and Fourier-transform infrared spectroscopy9. Therefore, the EHDAC has become a useful tool to study various material properties at HPHT conditions, such as phase stability and transitions10,11, melting curves12, thermal equation of state13, and elasticity14.
The BX-90 type DAC is a newly developed piston-cylinder type DAC with large aperture (90&#176; at maximum) for XRD and laser spectroscopy measurements9, with the space and openings to mount a miniature resistive heater. The U-shaped cut on the cylinder side also provides room to release the stress between the piston and the cylinder side caused by temperature gradient. Therefore, it has recently been widely used in powder or single-crystal XRD and Brillouin measurements with the external-heating setup. In this study, we describe a reproducible and standardized protocol for preparing EHDACs and demonstrated single-crystal XRD as well as Brillouin spectroscopy measurements of synthesized single-crystal ice-VII using the EHDAC at 11.2 GPa and 300-500 K.

<table>
	<tbody>
		<tr>
			<td>Au</td>
			<td>N/A</td>
			<td>N/A</td>
			<td>for pressure calibration</td>
		</tr>
		<tr>
			<td>Deionized water</td>
			<td>Fisher Scientific</td>
			<td>7732-18-5</td>
			<td>for the starting material of ice-VII synthesis</td>
		</tr>
		<tr>
			<td>Diamond anvil cell</td>
			<td>SciStar, Beijing</td>
			<td>N/A</td>
			<td>for generating high pressure</td>
		</tr>
		<tr>
			<td>K-type thermocouple</td>
			<td>Omega</td>
			<td>L-0044K</td>
			<td>for measuring high temperature</td>
		</tr>
		<tr>
			<td>Mica</td>
			<td>Spruce Pine Mica Company</td>
			<td>N/A</td>
			<td>for electrical insulation</td>
		</tr>
		<tr>
			<td>Pt 10wt%Rh</td>
			<td>Alfa Aesar</td>
			<td>10065</td>
			<td>for heater</td>
		</tr>
		<tr>
			<td>Pyrophyllite</td>
			<td>McMaster-Carr</td>
			<td>8479K12</td>
			<td>for fabricating the heater base</td>
		</tr>
		<tr>
			<td>Re</td>
			<td>Sigma-Aldrich</td>
			<td>267317</td>
			<td>for the gasket of diamond anvil cell</td>
		</tr>
		<tr>
			<td>Resbond 919 Ceramic Adhesive</td>
			<td>Cotronics Corp</td>
			<td>Resbond 919-1</td>
			<td>for insulating heating wires and mounting diamonds on seats</td>
		</tr>
		<tr>
			<td>Ruby</td>
			<td>N/A</td>
			<td>N/A</td>
			<td>for pressure calibration</td>
		</tr>
		<tr>
			<td>Ultra-Temp 2300F ceramic tape</td>
			<td>McMaster Carr Supply</td>
			<td>390-23M</td>
			<td>for thermal insulation</td>
		</tr>
	</tbody>
</table>

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.

In this report, we used the fabricated resistive micro-heater and BX-90 DAC for the EHDAC experiment (Figure 1 and Figure 2). Figure 1 shows the machining and fabrication processes of the ring heaters. The standard dimensions of the heater base are 22.30 mm in outer diameter, 8.00&#160;mm in inner diameter and 2.25 mm in thickness. The dimensions of the ring heater can be adjusted to accommodate various types of seats and diamonds.<...

Watch this Scientific Journal Video about An Externally-Heated Diamond Anvil Cell for Synthesis and Single-Crystal Elasticity Determination of Ice-VII at High Pressure-Temperature Conditions at JoVE.c

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

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

Externally-heated diamond anvil cell can generate simultaneously high pressure and high temperature, to simulate the conditions in ours and other planets'interiors. The main advantage of this technique is that it can be combined with various spectroscopic techniques, such as optical microscopy, x-ray diffraction, Raman spectroscopy, and Brillouin scattering. This technique is used to study interiors of rocky planets and the moon.It can also be used to investigate the material property under extreme condition in solid state physics and chemistry. The most challenging part of this protocol is the placement and the fixture of thermal couple to the diamonds. It is important to carefully follow the instruction when performing these steps.This protocol involves many hands-on steps, for where your demonstration is critical, in order to provide sufficient details for the audience to follow. Begin by cutting the platinum rhodium wire into three equal lengths, approximately 44 centimeters each. Carefully wind each wire through the holes in the heater base, leaving about 10 centimeters outside of the heater base for connection to the power supply.Make sure that the wire is lower than the gutters of the base. If it's higher than the gutter, use a proper flathead screwdriver to press it down. Wind more wires on the 10 centimeter extension wires, to reduce the electrical resistance.Use two small ceramic electrical insulating sleeves to protect the wires, extending outside the ring heater base. Mix cement adhesive with water, at a ratio of 100 to 13, and use the mixture to fix those tubes to the ring heater base. Then allow the cement to cure.Electrically insulate the wire by attaching one mica ring to each side of the heater with adhesive putty. Use mounting jigs to align the diamonds with backing seats. Then glue the diamond to the backing seat with black epoxy.The black epoxy should be lower than the girdle of the diamond, to leave some space for the high temperature cement. To thermally insulate the seats and the diamond anvil cell, or DAC, glue mica or place mica rings under the seats. Put the seats with the diamonds into a BX90 DAC.And align two diamonds under the optical microscope. Place the rhenium gasket between the two diamonds, and gently tighten the four screws of the DAC to pre-indent the gasket to approximately 30 to 45 micrometers. Drill a hole at the center of the indentation with an electrical discharge machine, or a laser micro-drilling machine.Fix two small pieces of mica with the cement mixture on the seat of the piston side of the DAC, to electrically insulate the thermal couples from the seat. Attach two K-type or R-type thermal couples to the piston side of the DAC, ensuring that the tips of the thermal couples touch the diamond close to the culet. Then, use the high temperature cement mixture to fix the thermal couple position, and cover the black epoxy on both sides of the DAC.Use the carbon dioxide laser drilling machine to cut the 2300 degree Fahrenheit ceramic tape in the shape of the heater base, and place it on both sides of the DAC, fixing it with adhesive putty if necessary. Place the heater on the piston side of the BX90 DAC, and use some ceramic tape to fill the gap between the heater and the DAC wall. Clean the sample chamber hole of the gasket with a needle, to get rid of the metal fragments introduced by the drilling.Then use an ultrasonic cleaner to clean the gasket for 5 to 10 minutes. Put two small balls of adhesive putty around the diamond on the piston side of the DAC to support the gasket. Then align the sample chamber hole of the gasket to match the center of the culet, under the optical microscope.Load one or more ruby spheres and one piece of gold into the sample chamber. Then load a drop of distilled water in the sample chamber. Close the DAC and compress it, by tightening the four screws.Determine the pressure of the sample by measuring the fluorescence of ruby spheres with a Raman spectrometer. Carefully compress the sample by turning the four screws. And monitor the pressure until it reaches the stability field of Ice VII.The target pressure is usually between 2 and 10 gigapascal at 300 Kelvin. Put the externally-heated DAC under the optical microscope with a camera connected to the computer. Thermally insulate the DAC with the microscope stage, without blocking the transmitted light path of the microscope.Connect the thermal couple to the thermometer, and connect the heater to a DC power supply. Monitor the melting of Ice VII crystals, upon heating to a temperature that is higher than the melting temperature of the high pressure Ice VII. Quench the sample chamber to allow the liquid water to crystallize.Then increase the temperature until some of the smaller ice crystals are molten. Repeat the heating and cooling cycles a few times, until only one or a few larger grains remain in the sample chamber. The compressed water sample was heated to an externally-heated DAC at about six gigapascal, up to 850 Kelvin, to make a single crystal Ice VII.A large single crystal was synthesized after several cycles of heating and cooling. The synthesized single crystallized VII was utilized for synchrotron x-ray diffraction, and Brillouin spectroscopy, at high pressure and high temperature. The temperature power relationship was determined.The crystal had little lattice stress and retained its good quality after compression and heating. As indicated by the sharp Bragg diffraction peaks at synchrotron-based single crystal x-ray diffraction images. The diffraction pattern can be indexed with a cubic structure.The sound velocities and elastic moduli were obtained by high pressure and high temperature Brillouin scattering measurements. While attempting this protocol, the placement of thermal couples is very important. The thermal couples should be electrically insulated around the seats and the DAC, and it should be close to the culet of diamond.The external-heated diamond anvil cell is often combined with Ramen, FTIR, and numerous synchrotron radiation spectroscopic methods, such as x-ray diffraction, combined with the properties of materials in situ at high pressure in high temperature conditions. For those who are familiar with diamond anvil cell, this technique can be easily learned to enable performance on not only high pressure, but also high temperature measurements in future studies.

an-externally-heated-diamond-anvil-cell-for-synthesis-single-crystal

Research

JoVE Journal

Chemistry

5.7K Görüntüleme.  China University of Geosciences (Wuhan). Harici ısıtmalı elmas örs hücresi aynı anda yüksek basınç ve yüksek sıcaklık üretebilir, bizim ve diğer gezegenlerin iç koşulları simüle etmek için. Bu tekniğin en büyük avantajı optik mikroskopi, x-ışını kırınımı, Raman spektroskopisi ve Brillouin saçılma gibi çeşitli spektroskopik tekniklerle kombine edilebilmektedir. Bu teknik kayalık gezegenlerin ve ayın iç mekanlarını incelemek için kullanılır.Aynı zamanda katı hal fiziği ve kimya aş?...

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