Electronic Moments Induced by Nuclear Moments in Van Vleck Compounds

In the Van Vleck compound $\left({\mathrm{Pr}}_x{\mathrm{La}}_{1-x}\right){\mathrm{Sn}}_3$, we have attained the saturation of nuclear magnetization. The observed saturation value decreases with increasing applied magnetic field. A simple model of "nuclear field" accounts well for this effect. The nuclear moment is enhanced by an electronic contribution equal to the field derivative of the electronic magnetization times the nuclear field.