NMR Study of Weakly Itinerant Ferromagnetic Y(Co1-xAlx)2

Abstract

The hyperfine field, H hf , and the nuclear spin-lattice relaxation rate, 1/ T 1 , of 59 Co and 27 Al nuclei have been measured in the weak itinerant ferromagnets Y(Co 1- x Al x ) 2 . The temperature and magnetic field dependence of 1/ T 1 T has been found to be well described by the self-consistent renormalization (SCR) theory of spin fluctuations. From the experimental data of the nuclear relaxation and the magnetization, the parameters characterizing the spin fluctuations in these materials were estimated. The temperature dependence of the magnetic susceptibility was calculated using these values in the framework of the SCR theory. The calculated results well reproduce the observed susceptibility, supporting the quantitative validity of the SCR theory. It has also been shown that a theoretical relation between these parameters proposed recently is consistent with the experimental data.