Nuclear spin lattice relaxation of191 mIr in Fe

Abstract

Thermal cycling of the lattice temperature was used to determine the nuclear spin lattice relaxation of191 mIr Fe in polarizing fields of 0.05 to 1.3 T. At low temperatures, the relaxation time is not very much shorter than the lifetime of191 mIr. In the first part of the paper, the master equation formalism is extended to include a finite lifetime. Our result for the reduced relaxation constant, γ2CK=(1.48±0.11)·1014 K s-1 T-2 (high field limit) is in serious disagreement with that of a spin echo measurement of193Ir Fe, but fits much better into the general systematics. A comparison of relaxation rates for 3 d-, 4 d-, and 5 d-impurities in Fe is given. As a by-product, a Kapitza conductivity constant of lK=1.5 mW cm-2 K-4±30% was found between Fe and dilute3He/4He. © 1981 Springer-Verlag.