Pyromagnetic domain walls connecting antiferromagnetic non-ferroelastic magnetoelectric domains

We describe a group-theoretical procedure that enables one to find necessary conditions for the appearance of spontaneous magnetization in domain walls. We illustrate the derivation of wall symmetries on example of Cr2O3 and present a brief summary of a systematic analysis of domain walls in antiferromagnetic non-ferroelastic and magnetoelectric phases which shows that in more than 50% of possible domain walls a spontaneous magnetization may appear.