抄録
In the measurement of nuclear spin-lattice relaxation time, T1 of Mn55 in ferrimagnetic Mn4N the effects of domain wall and of spin diffusion were successfully excluded by applying an external magnetic field higher than 3 kOe and an rf field higher than 1 Oe. T1T=1.4sec °K in the range of T=1.8°K to 77°K, where the Fermi contact interaction of 4s conduction electrons is considered to be responsible for the nuclear relaxation. The present state density of 3d band electrons at Fermi surface is estimated to be very small compared with those in various transition metals. Moriya’s theory of nuclear relaxation in ferromagnetic metal was used here. The deviation from the above relation arises above 77°K. It is suggested that the nuclear relaxation is attributable to the two magnon process through anisotropic hyperfine interaction.