Magnetoelastic excitations in Y-Fex films

Abstract

Conventional microwave resonance, pulse‐echo, and spin‐phonon spectrometer experiments on vacuum evaporated microcrystalline and amorphous films of YFe_x(x?2) demonstrate the existence of significant dynamic magnetoelastic coupling. For microcrystalline specimens, multiple transverse phonon signal peaks are observed at the rf frequency as a function of static field applied parallel to the film normal. The applied magnetic fields (0–20 kOe) for which the phonon signals are observed coincide with resonance absorption signals. In addition, the resonance data contain well‐resolved structure with as many as 8 peaks. To date, no high field multiple peak structure has been observed in amorphous films. Pulse‐echo and spin‐phonon spectrometer experiments have also shown that phonons are excited with parallel rf and dc fields in the film plane. A maximum longitudinal signal is observed with this field configuration; the signal intensity varies approximately as cos⁴φ, where φ is the angle between the rf and dc fields. With the fields in the film plane, a maximum transverse phonon signal is observed at φ=90°.