Growing of Thick Single-Crystalline La-Substituted Yttrium-Iron Garnet Films with Reproducible Parameters
Basic principles of growing the thick (35–60 мm) single-crystalline La-substituted yttrium-iron garnet (Y3−xLaxFe5O12, La :YIG) films with reproducible parameters have been formulated. La :YIG films are grown on gallium-gadolinium garnet (Gd3Ga5O12) substrates from a supercooled melt-solution (MS) consisting of Y2O3, La2O3, and Fe2O3 oxides and the PbO–B2O3 solvent. In order to minimize the implantation of Pb2+ ions into the films, which degrades the film quality, the epitaxy has to be performed at high temperatures and a low MS supercooling. It is found that, in order to maintain a constant growth rate of La :YIG films with reproducible parameters, a large MS mass (10–16 kg) has to be used, and the MS temperature has to be permanently lowered at a rate of 0.042 K/min.