Phase transitions in bubble-domain structures upon spin reorientation in garnet ferrite films

The behavior of a hexagonal bubble lattice in a (BiTm)(3)(FeGa)(5)O-12 garnet ferrite uniaxial film with a compensation point of 120 K is investigated experimentally in the range of the crossover from easy-axis magnetization anisotropy to easy-plane magnetization anisotropy. It is demonstrated that the spin reorientation occurs in the temperature range 185-160 K, in which the angular phase Phi(angle) (or (Phi) over bar (angle)) coexists with the axial phase Phi(<111>). At 172 K, when the percentage of the angular phase becomes equal to the percentage of the axial phase, the bubble-lattice parameters and domain-wall width are characterized by a jump. In the range T < 160 K, there exists only the easy-plane phase. (C) 2004 MAIK Nauka / Interperiodica.