文章基本信息

标题：Physical mechanism of δ-δ′-ε phase stability in plutonium
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作者：Chun-Mei Li ; Börje Johansson ; Levente Vitos 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2017
卷号：7
期号：1
DOI：10.1038/s41598-017-06009-1
语种：English
出版社：Springer Nature
摘要：Based on first-principle calculations, we have systematically explored the nature of the elastic stability and the δ-δ'-ε phase transitions in pure Pu at high temperature. It is found that, both the electron-phonon coupling and the spin fluctuation effects tend to decrease the tetragonal elastic constant (C') of δ-Pu, accounting for its anomalous softening at high temperature. The lattice thermal expansion together with the electron-phonon coupling can stiffen C' of ε-Pu, promoting its mechanical stability at high temperature. The δ-ε transition is calculated to take place around 750-800 K, and is dominated by the phonon vibration. The δ' intermediate phase is realized around 750 K mainly because of the thermal spin fluctuation.