Interplay between hybridization gaps and antiferromagnetic gap in the hole-doped Kondo semiconductor Ce(Os1-yRey)2Al10

International Conference on Strongly Correlated Electron Systems 2016

Kawabata, Jo^1 ; Ekino, Toshikazu^2 ; Yamada, Yoshihiro^1 ; Sugimoto, Akira^2 ; Muro, Yuji^3 ; Takabatake, Toshiro^1,4

Department of Quantum Matter, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima

739-8530, Japan^1

Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima

739-8526, Japan^2

Liberal Arts and Sciences, Faculty of Engineering, Toyama Prefectural University, Imizu, Toyama

939-0398, Japan^3

Institute for Advanced Materials Research, Hiroshima University, Higashi-Hiroshima

739-8521, Japan^4

关键词: Antiferromagnetic orders;    Antiferromagnetics;    C-f hybridization;    Hole-doped systems;    Kondo semiconductors;    Magnetic correlation;    Sommerfeld coefficient;    Tunneling measurement;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/807/1/012008/pdf
DOI  :  10.1088/1742-6596/807/1/012008

来源: IOP

【 摘 要 】

The Kondo semiconductor CeOs2Al10undergoes an antiferromagnetic (AFM) order at an unexpectedly high temperature 28.5 K. We have performed break junction tunneling measurements for the hole-doped system Ce(Os1-yRey)2Al10(y ≤ 0.1). The tunneling spectrum dI/dV for y = 0 displays successive openings of a hybridization gap V1, an AFM gap VAFand another hybridization gap V2in the density of states (DOS). On cooling from 36 K to TN, both the gap value V1and the DOS at the Fermi level, EF, decrease by 8% of the values at 36 K. This fact indicates that the development of short-range magnetic correlations reduces the c-f hybridization gap. For y = 0.02, a peak appears in dI/dV at V = 0 concurrently with the disappearance of V2. With increasing y further, the in-gap states develop at EF, in good agreement with the increase in the Sommerfeld coefficient of the heat capacity. Thereby, TN, V1and VAFdecrease and disappear at y = 0.05. These facts provide compelling evidence that the presence of V1is necessary for the AFM order in CeOs2Al10.