Critical phenomena at diamagnetic phase transitions

Abstract

The critical phenomena near diamagnetic phase transitions and in the domain phase are considered. Possibilities of the soft-mode existence and the static critical effect in susceptibility related to the appearance of Condon domains in aluminium are discussed. The constructed phase diagram and the temperature behaviour of the susceptibility give the value of the phase-transition temperature observed in aluminium. We present the temperature dependence of the magnetisation in each domain being the order parameter of the diamagnetic phase transition and confirming the softening of the orbital magnon-mode in aluminium. Calculations of the spectral density of excitations at diamagnetic phase transitions are made in order to explain the critical growth of the helicon damping observed in aluminium. The temperature dependence of the damping coincides with that measured in aluminium. The calculated magnetic-induction splitting due to Condon domains turns out to be close to that estimated in muon rotation spectroscopy experiment.