Theoretical Study of the Dynamic Effect Caused by Low-Symmetric Distribution of Spins on EPR Spectra in One-Dimensional Systems by the Method of Memory Function

Abstract

The fact that the low-symmetric distribution of spins causes the prominent effect on EPR spectra in exchange-interacting one-dimensional paramagnets is verified by the theoretical study on the basis of Morri's memory function method. The characteristic contribution from this effect, which vanishes completely in cases for the high-symmetric distribution of spins, is taken into account in the derivation of spectral function. Obtained spectra depend, in consequence, on the relation between the directions of one-dimensional chain-axis and vibrational field, as well as on that of chain-axis and static field. Characteristic features of the spectra (distortions of lineshape, linewidths and shifts of resonance field) agree well with those of observations in (CH 3 ) 4 NMnCl 3 (TMMC).