NMR Studies of the Spinel-Type Cu(Cr1-xHfx)2S4

27th International Conference on Low Temperature Physics

Niki, H.^1 ; Higa, N.^1 ; Kuroshima, H.^1 ; Toji, T.^1 ; Oshiro, M.^1 ; Yogi, M.^1 ; Ebisu, S.^2 ; Nagata, S.^2

Department of Physics, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa

903-0213, Japan^1

Muroran Institute of Materials Research, Muroran, Hokkaido

980-8577, Japan^2

关键词: Conduction electrons;    Core polarization;    Low temperature regions;    Low temperatures;    Microscopic points;    Temperature dependence;    Temperature dependencies;    Temperature regions;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/568/4/042021/pdf
DOI  :  10.1088/1742-6596/568/4/042021

来源: IOP

【 摘 要 】

To investigate the magnetic properties of the Hf-rich side (0.5 ≤ x ≤ 1.0) of Cu(Cr1-xHfx)2S4from a microscopic point of view,63Cu NMR has been performed at temperatures between 4.2 and 300 K. Temperature dependencies of the Knight shift and spin- lattice relaxation time (T1) have been measured. As for 0.7 ≤ x ≤ 1.0, the Knight shift gradually shifts to a negative side with decreasing temperature due to the core polarization of d conduction electrons. The temperature dependence of 1/T1T in this range of x indicates that the T1T is constant in all temperature region. On the other hand, in the range of 0.5 ≤ x ≤ 0.7, the Knight shift rapidly shifts to negative side below about 130 K because of the core polarization of d conduction electrons. In this range of x, the values of 1/T1T at high and low temperatures take constant values. The value at low temperatures is approximately twice compared with those at high temperatures. The density of state at the Fermi level in the low temperature region would be about 1.3 times larger than that in the high temperature region.