Spin-wave resonances in nonuniformly strained films of FeBO3

Spin-wave resonances are investigated in thin films of the antiferromagnet FeBO₃ with magnetic anisotropy of the easy-plane type. It is observed that high-order resonances are observed only when nonuniform stresses are created in the sample. In nonuniformly stressed samples the antiferromagnetic resonance lines are broadened, and against the background of this broadening spin-wave resonances are visible whose positions are well described within the free-particle approximation. Using this method it is possible to resolve resonances with wave numbers ≃1.5×10⁵ cm⁻¹. The presence of strong uniaxial elastic stresses is established experimentally in nonuniformly strained films. A contact mechanism for exciting spin-wave resonances is discussed. Zh. éksp. Teor. Fiz. 112, 564–573 (August 1997)