In-situ combined X-ray diffraction and electrical resistance measurements at high pressures and temperatures in diamond anvil cells

摘要

A method of simultaneous X-ray diffraction and electrical resistance measurements of materials in a diamond anvil cell has been developed. The experimental arrangement for the electrical measurements uses a gasket as a part of the electrode scheme. Application of the new methodology is demonstrated on the examples of the study of high-pressure high-temperature behavior of Pr and Fe-Ni alloys. Simultaneously obtained diffraction and resistance data provide the different, from earlier studies, interpretations of the topology of the dhcp-fcc phase transition in the phase diagram of Pr. Namely, the shape of a hysteretic region is mostly defined by kinetics of the dhcp phase growth rather than by thermodynamic driving force at the fcc to dhcp phase transformation. The results of combined X-ray diffraction and resistance measurements of Fe{sub}0.8Ni{sub}0.2 alloy up to 18 GPa and 425 K are reported along with the complementary resistance measurements of Fe{sub}0.9Ni{sub}0.1 alloy.