Mössbauer relaxation studies of non-linear dynamical excitations in low-dimensional magnets

• DOI: 10.1007/bf02354747
• Publication Date: 2006-04-06T23:08:30Z
• Authors: H. J. M. de Groot; L. J. de Jongh; M. Elmassalami; H. H. A. Smit; R. C. Thiel
• Keywords: Chain (unit); Domain wall (magnetism)

Mossbauer effect spectroscopy provides an excellent probe to study domain wall dynamics in the quasi 1-d Ising-type magnetic chain. Theoretical aspects of moving domain walls (nonlinear excitations, kinks, solitons) are briefly discussed, both for quantum and classical 1-d systems. We review experimental data on Fe(N2H5)2(SO4)2, RbFeCl3·2H2O and FeCl2 (NC5H5)2. Analysis of the spectra is performed in two different ways: by extracting linewidths, and by fitting to the Blume-Tjon relaxation model, which is argued to give the exact description for the Mossbauer spectrum of a magnetic chain, subject to free-kink behaviour. Differences between this theory and experiments are discussed.