Phase Transition of Y2BaCuO5

Phase transition of Y2BaCuO5 has been studied by X-ray diffraction, thermal gravimetric and differential thermal analyses. At temperatures higher than 1265°C in air, the transition has a body-centered cubic structure with a probable space group of Ia3 and the lattice constant of a=1.0602 nm. The transition temperature T c(°) from the well known orthorhombic phase to the cubic one was changed depending heavily on the oxygen partial pressure P(atom) as T c=1295+47.5 log P.