A new custom-designed system for a 3000 ton multi-anvil press has been developed to reach temperatures below room temperature at high pressures. The system was designed to remove heat selectively and conductively from the sample volume through six of the eight tungsten carbide (WC) cubes in direct contact with the octahedral pressure cell. The key components of the system include Cu cooling fins sandwiched between neighboring cube faces and the connected Cu heat exchange chamber through which liquid nitrogen flows. Currently, this system enables us to reach temperatures down to 220 K at pressures up to 8 GPa, but it can be easily modified to retain similar cooling capability at the highest pressure the press can reach (ca. 25 GPa).
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1063/1.4969054 | DOI Listing |
Chemistry
July 2024
Department of Chemistry, University of Massachusetts Amherst, Amherst, MA 01003, United States.
Transition metal carbides find widespread use throughout industry due to their high strength and resilience under extreme conditions. However, they remain largely limited to compounds formed from the early d-block elements, since the mid-to-late transition metals do not form thermodynamically stable carbides. We report here the high-pressure bulk synthesis of large single crystals of a novel metastable manganese carbide compound, MnC (P6/mmc), which adopts the anti-NiAs-type structure with significant substoichiometry at the carbon sites.
View Article and Find Full Text PDFRev Sci Instrum
January 2024
Bayerisches Geoinstitut, University of Bayreuth, Bayreuth, Germany.
Sci Rep
June 2022
Department of Earth Sciences, University of Western Ontario, London, ON, N6A5B7, Canada.
Electrical resistivity measurements of Fe-10wt%Ni-10wt%Si have been performed in a multi-anvil press from 3 to 20 GPa up to 2200 K. The temperature and pressure dependences of electrical resistivity are analyzed in term of changes in the electron mean free path. Similarities in the thermal properties of Fe-Si and Fe-Ni-Si alloys suggest the effect of Ni is negligible.
View Article and Find Full Text PDFRev Sci Instrum
May 2022
Earth and Planets Laboratory, Carnegie Institution of Washington, Washington, District of Columbia 20015, USA.
On the basis of the van der Pauw method, we developed a new technique for measuring the electrical resistivity of metals in a cubic multi-anvil high-pressure apparatus. Four electrode wires were introduced into the sample chamber and in contact with the pre-pressed metal disk on the periphery. The sample temperature was measured with a NiCr-NiSi (K-type) thermocouple, which was separated from the sample by a thin hexagonal boron nitride layer.
View Article and Find Full Text PDFRev Sci Instrum
November 2021
Bayerisches Geoinstitut, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany.
We report a new rapid-quench technique for the Kawai-type multi-anvil press: several important improvements were made to our previous design. As a result, we are able to routinely quench melts with low glass-forming ability and form glasses. Owing to the use of 3D-printed parts to supply the coolant, the new design is easier to assemble and demonstrates better temperature stability and cooling rate.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!