We report on temperature-dependent broadband ferromagnetic resonance studies of magnetite (Fe3O4) film of thickness 30 nm grown on magnesium gallate [MgGa2O4(001)] single crystal substrate by pulsed laser deposition. The isotropic point, i.e., the temperature at which magnetocrystalline anisotropy vanishes, is found to be approximately 120 K, which is 10 K lower than the bulk value. The Verwey transition is close to 110 K, again about 10 K lower than the bulk crystal value. Below the Verwey transition temperature, the uniaxial anisotropy of the monoclinic phase increases gradually and asymptotically approaches a constant value indicating a smooth structural transition rather than a sudden change. Resonance linewidth and effective damping increase abruptly below 110 K. The effective damping constant is determined to be ~0.01 and is independent of temperature from 300 K to 120 K.

中文翻译：

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MgGa2O4(001)衬底上磁铁矿薄膜Verwey相变的铁磁共振研究

我们报告了通过脉冲激光沉积在镓酸镁 [MgGa2O4(001)] 单晶衬底上生长的厚度为 30 nm 的磁铁矿 (Fe3O4) 膜的温度相关宽带铁磁共振研究。发现各向同性点，即磁晶各向异性消失的温度约为 120 K，比体值低 10 K。Verwey 跃迁接近 110 K，再次比块状晶体值低约 10 K。在 Verwey 转变温度以下，单斜相的单轴各向异性逐渐增加并逐渐接近恒定值，表明结构转变是平滑的，而不是突然变化。共振线宽和有效阻尼在 110 K 以下突然增加。有效阻尼常数被确定为 ~0。