High-pressure phases of plutonium monoselenide studied by X-ray diffraction |
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| Authors: | M. Gensini E. Gering S. Heathman U. Benedict J. C. Spirlet |
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| Affiliation: | Commission of the European Communities, Joint Research Centre, Institute for Transuranium Elements, Postfach 2340 , D-7500, Karlsruhe, F.R.G. |
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| Abstract: | Abstract Plutonium monoselenide was studied under high pressure up to 47 GPa, at room temperature, using a diamond anvil cell in an energy dispersive X-ray diffraction facility. At ambient pressure, PuSe has the NaC1-type (B1) structure. The compound has been found to undergo a second-order crystallographic phase transition at around 20 GPa. This phase can be described as a distorted B1 structure, with a rhombohedral symmetry. PuSe transforms to a new phase at around 35 GPa, which can be indexed in the cubic CsCl-type (B2). The volume collapse at this phase transition is 11%. When releasing pressure, we observed a strong hysteresis to the inverse transformation down to 5 GPa. From the pressure-volume relationship, the bulk modulus has been determined to B 0 = 98 GPa and its pressure derivative as B 0 = 2.6. These results are compared to those obtained with other actinide monmictides and monochalcogenides. |
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