Volume collapse phase transitions in cerium-praseodymium alloys under high pressure |
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| Authors: | Christopher S. Perreault Nenad Velisavljevic Gopi K. Samudrala G. Kalai Selvan |
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| Affiliation: | 1. Department of Physics, University of Alabama at Birmingham, Birmingham, AL, USA;2. Shock and Detonation Physics Group (M-9), Los Alamos National Laboratory, Los Alamos, NM, USA |
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| Abstract: | Cerium-12at%Praseodymium(Ce0.88Pr0.12) and Ce-50at%Praseodymium(Ce0.50Pr0.50) alloy samples that contain a random solid-solution of Ce (4f1 (J?=?5/2)) and Pr (4f2 (J?=?4)) localized f-states have been studied by angle dispersive x-ray diffraction in a diamond anvil cell to a pressure of 65?GPa and 150?GPa respectively using a synchrotron source. Ce0.88Pr0.12 alloy crystallizes in a face-centered cubic (γ-phase) structure at ambient conditions, while Ce0.50Pr0.50 alloy crystallizes in the double hexagonal close packed (dhcp) structure at ambient conditions. Two distinct volume collapse transitions are observed in Ce0.88Pr0.12 alloy at 1.5?GPa and 18?GPa with volume change of 8.5% and 3% respectively. In contrast, Ce0.50Pr0.50 alloy shows only a single volume collapse of 5.6% at 20?GPa on phase transformation to α-Uranium structure under high pressure. Electrical transport measurements under high pressure show anomalies in electrical resistance at phase transitions for both compositions of this alloy. |
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| Keywords: | Rare earth alloys volume collapse X-ray diffraction electrical TRANSPORT |
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