X-ray absorption spectroscopy and novel electronic properties in heavy fermion compounds YbT2Zn20 (T: Rh and Ir)

International Conference on Strongly Correlated Electron Systems 2014

Honda, Fuminori^1 ; Hirose, Yusuke^2 ; Miyake, Atsushi^3 ; Mizumaki, Masaichiro^4 ; Kawamura, Naomi^4 ; Tsutsui, Satoshi^4 ; Watanuki, Tetsu^5 ; Watanabe, Shinji^6 ; Takeuchi, Tetsuya^7 ; Settai, Rikio^2 ; Aoki, Dai^1 ; O'Nuki, Yoshichika^8

Institute for Materials Research, Tohoku University, Oarai, Ibaraki

311-1313, Japan^1

Department of Physics, Niigata University, Niigata

950-2181, Japan^2

Institute for Solid State Physics, University of Tokyo, Kashiwa

277-8581, Japan^3

Japan Synchrotron Radiation Research Institute, Sayo, Hyogo

679-5198, Japan^4

Japan Atomic Energy Agency, Sayo, Hyogo

679-5148, Japan^5

Kyushu Institute of Technology, Fukuoka, Kitakyushu

804-8550, Japan^6

Low Temperature Center, Osaka University, Osaka, Toyonaka

560-0043, Japan^7

Department of Physics, University of the Ryukyus, Okinawa

903-0213, Japan^8

关键词: Ambient pressures;    Electronic specific heat coefficient;    Heavy fermion compounds;    Low temperatures;    Magnetic field dependences;    Measured temperatures;    Type structures;    Valence state;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/592/1/012021/pdf
DOI  :  10.1088/1742-6596/592/1/012021

来源: IOP

【 摘 要 】

YbT2Zn20(T: Rh and Ir), which crystallizes in the cubic CeCr2Al20-type structure, is a member of the well-known heavy fermion compounds, indicating a huge electronic specific heat coefficient γ500 mJ/(K2·mol). We have measured temperature and magnetic field dependences of Yb valence in YbT2Zn20(T: Rh and Ir) at ambient pressure by the Lm edge x- ray absorption spectroscopy in order to investigate the valence state of Yb 4f electrons in these compounds. It is revealed that the Yb valence in both compounds significantly decreases with temperature below about 100 K and increases with increasing magnetic field at low temperatures in contrast to the case of YbCo2Zn20.