NMR study of heavy fermion compound EuNi2P2

International Conference on Strongly Correlated Electron Systems 2014

Magishi, K.^1 ; Watanabe, R.^1 ; Hisada, A.^1 ; Saito, T.^1 ; Koyama, K.^1 ; Fujiwara, T.^2

Institute of Socio-Arts and Sciences, Tokushima University, Tokushima

770-8502, Japan^1

Graduate School of Science and Engineering, Yamaguchi University, Yamaguchi

753-8512, Japan^2

关键词: Heavy fermion compounds;    Korringa relations;    Magnetic excitations;    Microscopic views;    Nuclear Magnetic Resonance (NMR);    Nuclear spin lattice relaxation rate;    Relaxation mechanism;    Temperature range;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/592/1/012031/pdf
DOI  :  10.1088/1742-6596/592/1/012031

来源: IOP

【 摘 要 】

We report the results of31P-nuclear magnetic resonance (NMR) measurements on heavy fermion compound EuNi2P2in order to investigate the magnetic properties at low temperatures from a microscopic view point. The Knight shift has a negative value in an entire temperature range, and the absolute value increases with decreasing temperature but exhibits a broad maximum around 40 K, which is similar to the behavior of the magnetic susceptibility. Also, the nuclear spin-lattice relaxation rate 1/T1is almost constant at high temperatures above 200 K, which is reminiscent of the relaxation mechanism dominated by the interaction of the31P nucleus with fluctuating Eu-4f moments. Below 200 K, 1/T1gradually decreases on cooling due to the change of the valence in the Eu ion. At low temperatures, 1/T1does not obey the Korringa relation, in contrast to typical heavy fermion compounds. The nuclear spin-spin relaxation rate 1/T2shows the similar behavior as 1/T1at high temperatures. But, below 50 K, 1/T2increases upon cooling due to the development of the magnetic excitation.