钇铁柘榴石单晶薄膜在高功率下铁磁共振饱和现象和折叠效应

本文进一步研究了垂直泵作用下,钇铁柘榴石(YIG)单晶薄膜脉冲微波功率的铁磁共振吸收特性.实验结果表明:在较低微波功率下,低占空因子脉冲微波功率的铁磁共振曲线的主要特征是由于自旋波不稳定性引起共振线宽的变宽效应,而且增加磁场和减少磁场得到的共振曲线基本是相同的.在高微波功率下出现了铁磁共振的折叠效应.

THE SATURATION PHENOMENA AND FOLDOVER EFFECTS OF THE FERROMAGNETIC RESONANCE IN YIG SINGLE CRYSTAL FILMS AT HIGH POWERLEVELS

This paper further investigated the characters of the pulsed microwave power ferromagnetic resonance (FMR) absorption in YIG single crystal films under per-pendicular pumping. The single crystal YIG film samples (5.1μm thick and 500μm in diameter) were prepared by the liquid phase epitaxy on gadolinium gallium garnet substrates and photolithographic etching procedures. The pulsed microwave power FMR absorption curves were measured for three different configuration pum-pings at a frequency of 9.18GHz under room temperature. The experimental results show that the main character of the FMR profiles under pulsed microwave powers with low duty cycles is a linewidth broadening effect due to the spin-wave instability processes, and the up-sweep and down-sweep FMR profiles are basically identical. However, the foldover effects of the FMR profiles occur at the high power levels.