Scattering of surface magnetic polaritons from order-parameter fluctuations near second-order magnetic phase transitions

A study is reported of the scattering of surface magnetic polaritons in the vicinity of second-order spin-reorientational phase transitions, which is caused by spatial fluctuations of the order parameter. A four-sublattice an tiferromagnet alpha-Fe2O3 is used as an example to derive expressions for t he vacuum-scattered radiation near exchange magnetic-vibration frequencies. The scattering of surface magnetic polaritons is shown to be resonantly en hanced in characteristic regions of their spectrum. Estimates made for alph a-Fe2O3 indicate a possibility of experimental observation of surface magne tic-polariton scattering from fluctuations of the refractive index near sec end-order spin-reorientational phase transitions, (C) 2000 MAIK "Nauka/Int erperiodica".