EPR of Mn2+ study of phase transitions in K2ZnCl4

Temperature dependence of EPR spectra of Mn2+ ions is measured in commensurate(C), incommensurate(I) and paraelectric(PE) phases of K2ZnCl4 between 300 and 560 K. The analysis of EPR spectra relies of the well-established spin Hamiltonian of Mn2+ ions in a crystalline field of rhombic symmetry. The shifts and splittings of EPR lines in the I phase are calculated on the basis of phenomenological model of the incommensurate modulation. EPR signal in PE phase is very week and broadened. In the low-temperature range of the I phase the modulation wave exhibits soliton-like behaviour. (author)