We report the observation of damped oscillations of a single straight magnetic domain wall stabilized by an externally applied field gradient in a Gahyphen;YIG film (Y2.9La0.1Fe3.8Ga1.2O12). The measurements are performed at various field gradients, inhyphen;plane fields, and wall drive fields. We analyzed the results using the Landauhyphen;Lifshitzhyphen;Slonczewski (LLS) theory and obtained the wall width parameter Dgr;equiv; (A/Ku)1/2= (0.89plusmn;0.15) times;10minus;5cm and the corresponding wall massm0equiv; (2pgr;ggr;2Dgr;)minus;1= (5.2plusmn;0.9) times;10minus;11gthinsp;cmminus;2, whereAis the exchange constant,Kuis the uniaxial anisotropy constant, and ggr; is the gyromagnetic ratio of the material; the Gilbert damping constant agr;=0.005plusmn;0.001; and the reduced Landauhyphen;Lifshitz damping constant lgr;/ggr;2= (1.3plusmn;0.3) times;10minus;9Oe2thinsp;s. The wall mass according to Douml;ring as calculated from ggr;,A, andKuism0=lsqb;2pgr;ggr;2(A/Ku)1/2rsqb;minus;1= (8.1plusmn;0.6) times;10minus;11gthinsp;cmminus;2and is higher than the experimental value. The observed oscillations allowed an independent determination of the magnetization of the material (4.2plusmn;0.8 G) in agreement with a direct measurement (4.8plusmn;0.5 G). In an applied inhyphen;plane field of 262 Oe the peak velocity was 530 mthinsp;sminus;1. This value is lower by a factor of 1.6 compared to the peak velocity predicted from the LLS theory. From an observed asymmetry in the dependence of the wall oscillation frequency on the applied inhyphen;plane field we deduced that at the domain wall an effective inhyphen;plane field of 23plusmn;6 Oe is present, which is in the direction of the stray field at the filmhyphen;air interface. A model of a film having two layers is proposed to explain this field. At a low inhyphen;plane field we observed a wall oscillation with a low frequency, depending on the drive field amplitude. It is not excluded that this slow oscillation is due to a wall containing Bloch lines.
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