TEMPERATURE-CHANGES OF COERCIVITY IN GARNETS

The temperature dependence of domain wall coercive field, H-CW, of an epitaxial magnetic rare earth garnet film was modified by covering die garnet layer with sputtered SiO2. The result supports a recent model of domain wall coercivity. According to this model die typical shape o f the H-CW(T) curves originate ill die temperature dependence of the a nisotropy field, modified by several efficiency functions of the wall- defect interaction. The efficiency functions reflect predominance of d ifferent sets of sample defects within different temperature regions. Introduction of some extra stress, due to die sputtered SiO2, changed the wall-defect interaction in a certain ranee of temperatures and alt ered there the shape of the H-CW(T) curve. Characteristics of the orig inal system of defects and estimates of those: for thr modified sample are presented.