Abstract

The ferromagnetic resonance (FMR) spectra of epitaxial yttrium iron garnet films are experimentally studied. The field dependences of the FR frequency are used to determine the effective fields induced by the first and second anisotropy constants and the effective uniaxial anisotropy field. The FMR frequency and linewidth are found to increase in the fields lower than 8 Oe applied in the bismuth-containing film plane. This increase is related to the formation of a nonuniform magnetization distribution, which is supported by a direct magnetooptical observation. The FMR spectra are found to be modulated by a set of narrow lines, the amplitude of which is proportional to the FMR signal intensity. The frequency position of the lines is independent of the magnitude and direction of a dc magnetic field. This modulation is shown to be associated with the resonance excitation of transverse elastic vibration modes. The effective magnetoelastic coupling parameter and the linewidth of the elastic vibrations excited by resonance pumping are estimated.

中文翻译：

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外延钇铁石榴石薄膜中的铁磁共振和弹性振动

摘要

实验研究了外延钇铁石榴石薄膜的铁磁共振谱。FR频率的场依赖性用于确定由第一和第二各向异性常数以及有效单轴各向异性场引起的有效场。发现在含铋薄膜平面上施加的场强低于8 Oe时，FMR频率和线宽会增加。这种增加与不均匀磁化分布的形成有关，这由直接磁光观测支持。发现FMR频谱由一组细线调制，这些细线的幅度与FMR信号强度成正比。线路的频率位置与直流磁场的大小和方向无关。示出该调制与横向弹性振动模式的共振激励相关。估算了有效的磁弹性耦合参数和共振泵浦激发的弹性振动的线宽。