Growth of Magnetic Garnet Crystals

Single crystals of magnetic garnets have been grown from solutions of molten lead oxied, iron oxide, and the oxides of yttrium, samarium, erbium, or gadolinium. The crystals are grown by slowly cooling melts from 1325°C to near 900°C. A convenient composition is 52.5 mole % PbO, 44 mole % Fe2O3, and 3.5 mole % M2O3 where M is Y, Gd, Er, or Sm. Crystals of yttrium-iron garnet have been grown which contain gallium partially substituted for iron. The method may also be extended to the growth of nonmagnetic yttrium gallium garnets by using a melt which is 72.7 mole % PbO, 26 mole % Ga2O3 and 1.3 mole % Y2O3. Bismuth oxide can be used as a solvent for the growth of magnetic garnet crystals but the substitution of bismuth in the garnet lattice makes it less desirable than lead oxide.