HIGH-FREQUENCY MAGNETOELECTRIC EFFECTS IN FERROELECTRICS

The spectrum of elementary excitations of a ferroelectric in a magneti c field H parallel and perpendicular to a spontaneous polarization P w as calculated. In the case H parallel to P high-frequency susceptibili ty and interaction of electron excitations with electromagnetic waves were analyzed. It was shown that magnetic field induces a high-frequen cy magnetoelectric (ME) susceptibility and ME gyration in reflected an d transmitted light. ME gyration means the rotation of polarization pl ane of light at an angle proportional to the product (PH). For the tra nsmitted light the angle of ME gyration in the case H perpendicular to n (n is a normal to the surface) depends periodically on the path tra velled; and does not depend on the path if H parallel to n. ME gyratio n, in contrast to Faraday effect, is compensated at the double (forth and back) travel of light. Indicated ME effects are possible not only in ferroelectrics but also in a dielectric at the presence of constant electric and magnetic fields.