Perovskite oxides are perhaps the most studied family of compounds in solid-state chemistry due to their inherent abil to accommodate a wide range of elemental compositions and to display a wealth of structural variations. The transition-moat oxides in the double-perovskite structure can be represented by the A2BB06 formula (where A二alkaline earth or rare earth and BB are transition-metal Most of these alloys have been up to now found to take a rock-salt crystal structure, and ordered one of the alternate perovskite (octahedral) units B06 and $06 along three crystallographic axes.