Electromagnetic-acoustic transformation in an erbium single crystal

The temperature dependences of the electromagnetic-acoustic transformation (EMAT) efficiency and the velocity of transverse sound for the erbium rare-earth metal with three complex magnetic structures are experimentally investigated at different external constant magnetic fields. An intensive generation and anomalies in the velocity of transverse sound are revealed in the temperature range of the magnetic phase transitions. It is found that an increase in the magnetic field leads to an increase in the sound generation efficiency and a decrease in the anomalies in the velocity of sound. The relationships for the efficiency of transverse-sound generation through the magnetoelastic mechanism are theoretically derived for two magnetic structures of erbium. It is demonstrated that an increase in the EMAT efficiency in the phase transition range is associated with the specific features in the static and dynamic magnetic susceptibilities of erbium. (C) 2002 MAIK "Nauka/Interperiodica"