Phenomenological description of exchange relaxation processes in antiferromagnets

Abstract

Expressions are obtained for the exchange relaxation terms in the equations of motion for the magnetization and antiferromagnetism vectors in antiferromagnets and ferrites. The dissipative function is found. It is shown that from the general equations of motion for antiferromagnets in the dissipation-free approximation two relations are obtained between the time derivatives of the magnetization and antiferromagnetism vectors, thanks to which only two branches of the spin waves are realized. The decay of spin waves, calculated according to the microscopic and phenomenological theories, are compared. The mobility of the domain boundaries in antiferromagnets is calculated taking into account the exchange relaxation.