Nanostructured A2(RE,B)O6 (A = Ba, Sr; RE = Rare-Earth; B = Sb, Zr) Perovskite Ceramics and their Potential Applications in Microwave and Superconducting Electronics

A group of perovskites with general formula A2(RE,B)O6(A=Ba, Sr; RE=Rare-Earth; B=Sb, Zr) were synthesized as nanocrystals owing to the enhanced specific surface area that nanomaterials posses. These perovskites are characterized by varied crystal structure depends on the relative sizes of the cations occupying the A and B sites of the perovskite lattice. The new materials were either insulators or semiconductors. They possess moderate dielectric constant (~30) and relatively low dielectric loss (10-4); and therefore, they could be used as substrates in microwave circuits. Some of them falls to the semiconducting range with band gap ~3.3 eV; and therefore, could be used as transparent wide band gap semiconductors. Furthermore, the new perovskites were found to be chemically stable with two mostly considered high temperature ceramic superconductors for practical applications, viz. YBa2Cu3O7-δ(YBCO) and (Bi,Pb)2Sr2Ca2Cu3Ox(BSCCO).