Irreversible electric and magnetic effects in manganese perovskites

Microwave absorption and dc charge transport were studied in single crystals of manganese perovskites. Irreversible changes in dc electric conductivity were observed in a broad temperature range. Starting from 140 K and below, similar irreversible changes were observed in microwave field dependent absorption. Irreversibility T-H dependence was obtained. We explain these effects taking into account local lattice and magnetic phase transformation processes.