Zeroth-Order Nucleation Transition under Nanoscale Phase Separation

Materials with nanoscale phase separation are considered. A system representing a heterophase mixture of ferromagnetic and paramagnetic phases is studied. After averaging over configurations, renormalized Hamiltonian derived describing the coexisting phases. The characterized by direct exchange interactions an external magnetic field. properties studied numerically. stability conditions define stable state system. At temperature zero, in pure state. However, at finite temperature, for some interaction parameters, can exhibit zeroth-order nucleation transition between mixed transition, concentration appears via jump.