Влияние Внешних Факторов На Ширину Линии Ферромагнитного Резонанса В Структурах С Обменным Смещением

Abstract

Extrinsic factors contributing to the ferromagnetic resonance (FMR) line width in double layer (ferromagnet/antiferromagnet) systems with exchange bias were investigated. Dependence of the FMR line width on the thickness of the antiferromagnetic (AF) layer at a constant thickness of the ferromagnetic (F) layer and layers deposition order of the F - and AF - layers, as well as the correlation between the exchange bias and the surface roughness of the sample were studied. We found that the exchange bias has a minor, if any, contribution to the line width. In systems with an antiferromagnet deposited on a ferromagnetic layer, the width of the FMR line increases in proportion to the average size of the surface roughness. In systems with reversal layer sequence the uniaxial anisotropy provides a significant contribution to the line width. The width of the FMR line is in a quadratic dependence on the uniaxial anisotropy and inversely proportional to the thickness of the antiferromagnetic layer, which can be attributed to the effect of the microstructure evolution with the thickness as an extrinsic factor in the damping of the FMR.