INFLUENCE OF ANNEALING ON MAGNETIC-PROPERTIES OF A GE-DOPED GARNET FILM

An investigation of the influence of annealing (furnace annealing in an O2 atmosphere and local laser annealing) on the major magnetic properties of an Y1.5Sm0.3Ca0.9Lu0.3Fe4.1Ge0.9O12 epitaxial single-crystal bubble garnet film has been carried out. After furnace annealing a Ge-substituted film has shown a considerable drop of the saturation magnetization 4piM(s) and of the constant of the uniaxial anisotropy K(u). The kinetics of redistribution of Ge cations between the octa- and tetrahedral sites turned out to be comparatively slow, the activation energy E(a) amounting to 6.2 eV. Laser annealing caused a small increase of the collapse field H(c), which can be explained by slight randomization of the distribution of Y-Sm ions in the dodecahedral sublattice, while the Ge cations governing 4piM(s) remain on their sites.