Magnetooptical studies of the magnetic-field breakdown of the antiferromagnetic structure of iron carbonate. Depolarization of light in the magnetic transformation process
Abstract
The depolarization of light in a natural crystal of iron carbonate is investigated during the process of breakdown of its antiferromagnetic structure under the action of a pulsed magnetic field. It is shown that the depolarization of light is caused by magnetic inhomogeneities. Two methods are proposed for the formation of macroscopic inhomogeneities of the magnetization. One of these is associated with the formation of structural defects in the specimen during magnetic phase transitions in a pulsed field, the other is associated with magnetic phase lamination in the neighborhoods of the fields H1 and H2. From the experimental results it follows that the magnetic state of the specimen in the interval of fields (H1–H2) cannot be represented as a mixture or two magnetic phases. Under definite conditions the specimen is magnetically homogeneous in this region of fields (excluding narrow neighborhoods of the fields of the first order phase transitions H1 and H2).