Zn/Al-centered tetrahedral framework oxide Ba4Zn2Al2O9

Single crystals of Ba4Zn2Al2O9 were obtained by heating a mixture of BaCO3, ZnO, and Al2O3 at 1413 K in a dry air atmosphere. X-ray crystal structure analysis revealed that the compound crystalizes in a monoclinic cell (a = 6.9444(2) angstrom, b = 5.91650(10) angstrom, c = 13.5842(3) angstrom, beta = 103.955(1)degrees) with the space group P2(1) /n. The crystal structure can be characterized as a substitution of Zn/AlO4 tetrahedra for B-cation-centered O octahedra of a perovskite-type structure (ABO(3)). The vacant spaces surrounded by planes of the tetrahedra with eight- and tenfold coordinations of O atoms are occupied by Ba atoms. The melting temperature (1444 K), electrical conductivity (1.5 x 10(-6) S cm(-1) at 1073 K), relative permittivity (24 at 298 K and 1 MHz), and linear thermal expansion coefficient (9.72 x 10(-6) K-1 at 298-873 K) of a polycrystalline bulk sample were measured.

Automated summary

Single crystals of Ba4Zn2Al2O9 were obtained by heating a mixture of BaCO3, ZnO, and Al2O3 at 1413 K in a dry air atmosphere. The crystalline structure is characterized by a substitution of Zn/AlO4 tetrahedra for B-cation-centered O octahedra and occupied by Ba atoms. The physical properties like melting temperature, electrical conductivity, relative permittivity, and thermal expansion coefficient were measured for a polycrystalline bulk sample.