Experimental and theoretical results of surface acoustic-wave (SAW) propagation near the spin-reorientation region of ErFeO3 are presented. Velocity measurements of SAW were carried out at zero field and at various magnetic fields, applied in the reorientation plane. The SAW results, in comparison with various bulk measurements, exhibit a slightly narrower reorientation temperature region. An applied magnetic field suppresses the SAW velocity at the reorientation region and shifts the transition temperatures. The same effects were previously observed for longitudinal bulk waves propagating along the c axis of the crystal. The observed results are accounted for by using phenomenological magnetic and magnetoelastic free-energy expressions in the coupled equations of motion. It is concluded that the SAW interacts with antiferromagnetic modes of the bulk. The difference between the SAW and the bulk-wave results is attributed to the effect of the surface boundary on the magnetic anisotropy.
ASJC Scopus subject areas
- Condensed Matter Physics