MICROWAVE EXCITATIONS IN BI-DOPED GARNET-FILMS

Garnet films of the series (Bi,Lu)(3)(Fe,Mg)(5)O-12, with Bi contents of 0.85/f.u., have been investigated using microwave techniques. The s amples were 1.7-10 mu m thick, and were grown under different conditio ns. The uniaxial anisotropy and the resonance linewidths were evaluate d over the temperature range 4.2-300 K. The magnetostatic wave propaga tion losses in the interval 3-6 GHz were measured and correlated with the resonance linewidths and the sample growth conditions, For these s amples the resonance linewidth maxima occurred at about 50 K. The mini ma of the propagation loss and the resonance linewidth were obtained f or the film growth velocity upsilon = 0.88 mu m/min. The processes of microwave soliton formation and propagation have been observed experim entally in these Bi-doped garnet films. Under the continuous-wave regi me modulation instability was observed.