Indirect nuclear spin relaxation in ferromagnetic heavy rare earth metals

An investigation is presented of the low-temperature relaxation of nuclear spins in ferromagnetic heavy rare earth metals by the Suhl-Nakamura mechanism of virtual magnon exchange. Numerical estimates of the r.m.s. homogeneous linewidth and Bloch decay time T2 are made in 159Tb, 161Dy, 163Dy, using the 90 °K Tb dispersion data of Moller and Houmann. We find T2 values of approximately 2½, 25, 12 μs respectively. Sample inhomogeneous fields increase T2 slightly and thus these values are in reasonable agreement with the measurements of Kobayashi, Sano and Itoh, who find values about twice as large.