Field and temperature dependence of ¹⁵³Eu spin-lattice relaxation in ferromagnetic EuO

Abstract

Nuclear spin-lattice relaxation times, T1, of 153Eu have been measured in an irregularly shaped single crystal of EuO over the temperature range of 1.2°≦T≦4.2°K and magnetic field range of 0≦H0≦14 kOe for the crystal orientation H0⊥Hrf∥〈110〉 by use of the spin-echo technique. The relaxation process was found to satisfy T1 ∝ T-n, where n increases from approximately 2-3 as H0 increases from zero to 10 kOe. The T1 is essentially field independent up to H0≈2 kOe, Above this field there is a general increase in T1 but with an intermediate peak value at H 0≈6 kOe. The analysis of these data is complicated by the irregular shape of the sample and the high saturation magnetization, 4πM 0=24 kOe, for EuO. Within these limitations these results have been compared with the theory developed by Honma for EuS. © 1969 The American Institute of Physics.