Electromagnetic Generation of Acoustic Wavesnear Second-Order Magnetic-Phase Transitionsof the 'Order—Disorder' and 'Order—Order' Type

摘要

In this work, we theoretically and experimentally established the common feature of the evolutionof the efficiency of the electromagnetic generation of acoustic waves near the temperatures of second-ordermagnetic phase transitions characteristic of both the "order—disorder" (Curie point in isotropic ferromag-nets) and "order—order" (easy-axis—angular-phase and angular-phase—easy-plane) transitions in uniaxialmagnets, which consists in the fact that the peak of efficiency corresponds precisely to these temperatures atany values of the magnetic field even if in a magnetic field these temperatures cease to be the points of phasetransitions.