J. Phys. IV France 08 (1998) Pr2-303-Pr2-306
Temperature changes of coercivity in garnetsG. Vértesy1, I. Tomás2, J. Kadlecová2 and K. Metlov2
1 Hungarian Academy of Sciences, Research Institute for Materials Science, P.O. Box 49, 1525 Budapest, Hungary
2 Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 180 40 Praha 8, Czech Republic
The temperature dependence of domain wall coercive field, HCW, of an epitaxial magnetic rare earth garnet film was modified by covering the garnet layer with sputtered SiO2. The result supports a recent model of domain wall coercivity. According to this model the typical shape of the HCW(T) curves originate in the temperature dependence of the anisotropy field, modified by several efficiency functions of the wall-defect interaction. The efficiency functions reflect predominance of different sets of sample defects within different temperature regions. Introduction of some extra stress, due to the sputtered SiO2, changed the wall-defect interaction in a certain range of temperatures and altered there the shape of the HCW(T) curve. Characteristics of the original system of defects and estimates of those for the modified sample are presented.
© EDP Sciences 1998