Temperature-induced valence transition in EuNi2(Si1–xGex)2 investigated by high-energy resolution fluorescence detection X-ray absorption spectroscopy

Ryohei Shimokasa, Naomi Kawamura, Takayuki Matsumoto, Koki Kawakami, Taku Kawabata, Gen Isumi, Takayuki Uozumi, Akihiro Mitsuda, Hirofumi Wada, Masaichiro Mizumaki, Kojiro Mimura

Research output: Contribution to journalArticle

Abstract

Electronic structures of the temperature-induced valence transition system EuNi2(Si1–xGex)2 with x = 0.70, 0.79, 0.82 have been investigated by means of high-energy resolution fluorescence detection X-ray absorption spectroscopy (HERFD-XAS). The HERFD-XAS spectra clearly change their intensities of Eu2+ and Eu3+ components which directly reflect the temperature-induced valence transition. For x = 0.70, gradual spectral change exhibits a continuous valence transition, while drastic changes for x = 0.79 and 0.82 indicate first-order valence transitions. High-energy resolution measurements made it possible to observe additional fine structures which are recognized more clearly below the transition temperature. Existence of these fine structures suggests that many-body effect plays an important role in the temperature-induced valence transition of this system. The variation of Eu mean valence estimated from the HERFD-XAS spectra for each x correlates with that of magnetic susceptibility.

Original languageEnglish
Article number108150
JournalRadiation Physics and Chemistry
DOIs
Publication statusAccepted/In press - Jan 1 2020

All Science Journal Classification (ASJC) codes

  • Radiation

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