TY - JOUR A1 - Khandarhaeva, S. A1 - Fedotenko, T. A1 - Pakhomova, A. A1 - Gromilov, S. A1 - Dubrovinsky, L. A1 - Dubrovinskaia, N. A1 - Yusenko, Kirill T1 - Equations of state of rhodium, iridium and their alloys up to 70 GPa N2 - Knowledge of the compressional and thermal behaviour of metals and alloys is of a high fundamental and applied value. In this work, we studied the behaviour of Ir, Rh, and their fcc-structured alloys, Ir0.42Rh0.58 and Ir0.26Os0.05Pt0.31Rh0.23Ru0.15, up to 70 GPa using the diamond anvil cell technique with synchrotron X-ray diffraction. We found that all these materials are structurally stable upon room-temperature hydrostatic compression in the whole pressure interval, as well as upon heating to 2273 K both at ambient and high pressure. Rh, Ir0.42Rh0.58 and Ir0.26Os0.05Pt0.31Rh0.23Ru0.15 were investigated under static compression for the first time. According to our data, the compressibility of Ir, Rh, fcc–Ir0.42Rh0.58, and fcc Ir0.26Os0.05Pt0.31Rh0.23Ru0.15, can be described with the 3rd order Birch-Murnaghan equation of state with the following parameters: V0 = 14.14(6) Å3·atom−1, B0 = 341(10) GPa, and B0' = 4.7(3); V0 = 13.73(7) Å3·atom−1, B0 = 301(9) GPa, and B0' = 3.1(2); V0 = 13.90(8) Å3·atom−1, B0 = 317(17) GPa, and B0' = 6.0(5); V0 = 14.16(9) Å3·atom−1, B0 = 300(22) GPa, B0' = 6(1), where V0 is the unit cell volume, B0 and B0' – are the bulk modulus and its pressure derivative. KW - EOS KW - Rh-Ir alloys KW - High-entropy alloys KW - High-pressure PY - 2019 U6 - https://doi.org/10.1016/j.jallcom.2019.02.206 VL - 788 SP - 212 EP - 218 PB - Elsevier B.V. AN - OPUS4-47404 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -