Abstract: A spinel composition of the invention includes a monocrystalline lattice having a formula Mg1-w?wAlx-y?yOz, where w is greater than 0 and less than 1, x is greater than 2 and less than about 8, y is less than x, z is equal to or greater than about 4 and equal to or less than about 13, ? is a divalent cationic element having an ionic radius greater than divalent magnesium, and ? is a trivalent cationic element having an ionic radius greater than trivalent aluminum. The monocrystalline lattice has tetrahedral and octahedral positions, and most of the magnesium and ? occupy tetrahedral positions. In one embodiment, the molar ratio of aluminum to the amount of magnesium, ? and ? can be controlled during growth of the monocrystalline lattice thereby forming a spinel substrate suitable for heteroepitaxial growth of III-V materials. A method of the invention, includes forming a monocrystalline lattice of a spinel composition.

Abstract: A spinel composition of the invention includes a monocrystalline lattice having a formula Mg1−w&agr;wAlx−y&bgr;yOz, where w is greater than 0 and less than 1, x is greater than 2 and less than about 8, y is less than x, z is equal to or greater than about 4 and equal to or less than about 13, &agr; is a divalent cationic element having an ionic radius greater than divalent magnesium, and &bgr; is a trivalent cationic element having an ionic radius greater than trivalent aluminum. The monocrystalline lattice has tetrahedral and octahedral positions, and most of the magnesium and &agr; occupy tetrahedral positions. In one embodiment, the molar ratio of aluminum to the amount of magnesium, &agr; and &bgr; can be controlled during growth of the monocrystalline lattice thereby forming a spinel substrate suitable for heteroepitaxial growth of III-V materials. A method of the invention, includes forming a monocrystalline lattice of a spinel composition.