On the intensity of shock-initiated magnetoelastic oscillations arising in iron borate single crystals during pulsed magnetizing or magnetization-switching processes

The intensities of magnetoelastic oscillations accompanying pulsed 180° and 90° magnetization switching of iron borate single crystals as well as pulsed magnetization of the crystals from a demagnetized state (with zero total magnetic moment) are compared for the first time. The amplitude A ₁ of the oscillations of the signal obtained from the experimental sample by the induction method is adopted as a measure of the intensity of the magnetoelastic oscillations. It is found that for the same pulse heights of the magnetic field H exciting the magnetization-switching or magnetizing process, the amplitudes A ₁ of the oscillations observed in 90° magnetization-switching and initial-magnetization processes have practically the same value, which is $\sqrt 2 $ times smaller than the amplitude of the oscillations obtained in 180° magnetization switching (reversal). It is concluded on the basis of the result obtained that the intensity of the magnetoelastic oscillations is virtually independent of the initial state of the single crystal and is determined mainly by the energy density ΔM·H acquired by the magnetic subsystem of the crystal from the external field (ΔM is the change in magnetization). Hence it follows that when iron borate is used in fast modulators for Mössbauer γ rays it is preferable to use the 90° magnetization-switching regime rather than the magnetization regime as has been done until very recently.