Influence of Localized Rare-Earth Moments onSc45Nuclear Magnetic Relaxation

Abstract

Scandium-base alloys of 0.02 and 0.05 at.% of gadolinium and dysprosium have been studied using transient nuclear-magnetic-resonance techniques. The ${}_{}{}^{45}{}_{}{}^{}\mathrm{Sc}$ nuclear spin-lattice relaxation rate is enhanced in the rare-earth alloys. For $1.6<~T<~4.2$°K, the relaxation rate is described by $\frac{1}{T_1}={\left(\frac{1}{T_1}\right)}_{\mathrm{S}\mathrm{c}}[1+\frac{{\mathrm{KB}}_J\mathrm{}\left(x\right)\mathrm{}}{H}]$, where ${\left(\frac{1}{T_1}\right)}_{\mathrm{S}\mathrm{c}}$ is the pure scandium relaxation rate, $K$ is a constant, and $B_J\mathrm{}\left(x\right)\mathrm{}$ is the Brillouin function for $x$ $\equiv \frac{\mathrm{gJ}{\mu }_{\mathrm{B}}H}{k_{\mathrm{B}}T}$. The $T_1$ results are explained in terms of enhanced nuclear relaxation due to virtual excitation of the rare-earth magnetic moments.