Synchrotron x-ray spectroscopy studies of valence and magnetic state in europium metal to extreme pressures

TitleSynchrotron x-ray spectroscopy studies of valence and magnetic state in europium metal to extreme pressures
Publication TypeJournal Article
Year of Publication2012
AuthorsBi W, Souza-Neto NM, Haskel D, Fabbris G, Alp EE, Zhao J, Hennig RG, Abd-Elmeguid MM, Meng Y, McCallum RW, Dennis K, Schilling JS
Journal TitlePhysical Review B
Volume85
Pages205134
Date Published05
Type of ArticleArticle
ISBN Number1098-0121
Accession NumberWOS:000304395600004
KeywordsABSORPTION, elements, eu, gpa, intermediate-valence, MOSSBAUER, scattering, system
Abstract

In order to probe the changes in the valence state and magnetic properties of Eu metal under extreme pressure, x-ray absorption near-edge spectroscopy, x-raymagnetic circular dichroism, and synchrotron Mossbauer spectroscopy experiments were carried out. The Mossbauer isomer shift exhibits anomalous pressure dependence, passing through a maximum near 20 GPa. Density functional theory has been applied to give insight into the pressure-induced changes in both Eu's electronic structure and Mossbauer isomer shift. Contrary to previous reports, Eu is found to remain nearly divalent to the highest pressures reached (87 GPa) with magnetic order persisting to at least 50 GPa. These results should lead to a better understanding of the nature of the superconducting state found above 75 GPa and of the sequence of structural phase transitions observed to 92 GPa.

URL<Go to ISI>://WOS:000304395600004
DOI10.1103/PhysRevB.85.205134
Alternate JournalPhys. Rev. B