Relation between relaxation losses in domain-wall motion and ferromagnetic resonance in garnet films

Domain-wall mobility has been studied in garnet films having perpendicular magnetic anisotropy and a narrow FMR line. An analysis of the obtained and published experimental data shows that for the value of the Landau-Lifshits reduced damping parameter derived from FMR measurements, Lambda(FMR)>2.4X10(-9) Oe(2).s, the domain-wall mobility is inversely proportional to Lambda(FMR), which is in agreement with classical theory. For Lambda(FMR)<2.4X10(-9) Oe(2).s, the mobility decreases with decreasing Lambda(FMR). Possible reasons for this behavior are discussed. An empirical expression relating the losses entailed in domain motion to FMR-related losses for small Lambda(FMR) is proposed. (C) 1998 American Institute of Physics. [S1063-7834(98)02508-8].