Preparation of perovskite oxides for high T_c superconductor substrates

A variety of materials of the general type A₂BB′O₆ that have an ordered perovskite structure have been prepared and examined as possible substrate candidates for high T_c superconducting films. Materials containing either Ca or Sr as the A cation and either Ga or Al in combination with Nb or Ta as the B and B′ cations have been shown to be congruent melting compounds. These compounds have melting points easily accessible using conventional rf heating techniques and are therefore materials that could possibly be grown in bulk form using the Czochralski growth technique.