Phase transitions in domain walls

It has been proved that on approaching the line of (first-order or second order) transition between ordered phases a symmetry breaking necessarily occurs within a domain wall. The symmetry breaking in the cases under investigation takes place as a second-order phase transition. Calculations were performed for a reordering which was determined both by an appearance of the second order parameter and by the second component of a multi-component order parameter. The Landau potential for the description of phase transitions in the domain wall has been calculated and the regions of existence of high- and low-symmetry domain walls on the phase diagram have been determined, as well as anomalies of heat capacity and susceptibility at transitions in the domain walls.