Spin-Lattice Relaxation and Cross Relaxation in Nickel Thallium Tutton Salt

Abstract

Paramagnetic relaxation of single crystal NiTl₂(SO₄)₂·6HO₂O was studied by AC susceptibility measurement in magnetic field of 0∼20 kOe. It was possible to separate experimentally cross relaxation and lattice-bath relaxation from spin-lattice relaxation under appropriate condition. Above λ point of liquid He (T_λ), spin-lattice relaxation was strongly affected by lattice-bath relaxation and also by cross relaxation. Below T_λ, where lattice-bath relaxation was not observed, spin-lattice relaxation did not have such a strong effect of cross relaxation. Concentration dependence of cross relaxation time was also discussed. Cross relaxation time was temperature dependent especially at high magnetic field.