Evidence for multimagnon-mediated nuclear spin relaxation in the intertwining double-cain ferrimagnet $Ca_3 Cu_3 (PO_4)_4$
arXiv:cond-mat/0605157 · doi:10.1143/JPSJ.75.074703
Abstract
The nuclear spin-lattice relaxation time $T_1$ of $^{31}P$ nuclei in the title compound is measured for the first time and interpreted in terms of a modified spin-wave theory. We establish a novel scenario for one-dimensional ferrimagnetic spin dynamics -- it is three-magnon processes enhanced by exchange scattering, rather than Raman processes, that make the major contribution to $1/T_1$.
6 pages with 7 figures embedded