Origin of the black-golden transition in Sm1-xYxS

International Conference on Strongly Correlated Electron Systems 2014

Imura, Keiichiro^1 ; Saito, Mai^1 ; Kaneko, Masaki^2 ; Ito, Takahiro^2,3 ; Hajiri, Tetsuya^2 ; Matsunami, Masaharu^4,5 ; Kimura, Shin-Ichi^4,5,7 ; Deguchi, Kazuhiko^1 ; Suzuki, Hiroyuki S.^6 ; Sato, Noriaki K.^1

Graduate School of Science, Nagoya University, Nagoya

464-8602, Japan^1

Graduate School of Engineering, Nagoya University, Nagoya

464-8603, Japan^2

Nagoya University Synchrotron Radiation Research Center, Nagoya University, Nagoya

464-8602, Japan^3

UVSOR Facility, Institute for Molecular Science, Okazaki

444-8585, Japan^4

School of Physical Sciences, Graduate University for Advanced Studies (SOKENDAI), Okazaki

444-8585, Japan^5

Quantum Beam Center, National Institute for Materials Science, Tsukuba

305-0047, Japan^6

Graduate School of Frontier Biosciences, Physics Department, Osaka University, Osaka

565-0871, Japan^7

关键词: Angle resolved photoemission spectroscopy;    Critical concentration;    Different origins;    Doping concentration;    Hall effect measurement;    Metallic conductivity;    Semiconductor-to-metal transitions;    Valence transitions;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/592/1/012028/pdf
DOI  :  10.1088/1742-6596/592/1/012028

来源: IOP

【 摘 要 】

We report angle-resolved photoemission spectroscopy, electrical resistivity and Hall effect measurements on Sm1-xYxS. At the smallest doping concentration x 0.03, the system changes from a semiconducting to metallic conductivity, whereas it is at a critical concentration xc 0.19 that there occurs the volume collapse accompanied by a color change from black to golden. It appears that the band gap between 4f and 5d bands vanishes at xc. From these results, we suggest that the black-to-golden transition of Sm1-xYxS has the same mechanism as the pressure-induced valence transition of SmS, but the semiconductor-to-metal transition has a different origin for Sm1-xYxS and SmS.