Eine β-Tonerde mit Cu2+ in tetraedrischer Koordination: (Ba,Sr)CuAl10O17

A β-Alumina Containing Tetrahedric Coordinated Cu²⁺: (Ba, Sr)CuAl₁₀O₁₇ (Ba, Sr)CuAl₁₀O₁₇ single crystals can be obtained by reaction of BaCuO₂ and SrCuO₂ with Al₂O₃ in oxygen atmosphere ar 1400°C. It crystallizes with hexagonal symmetry, space group D–P6₃/mmc, a = 5.604; c = 22.678 Å; Z = 2. X-ray single crystal investigation led to the β-Alumina-type. Cu²⁺- and Al³⁺-ions occupy tetrahedra positions within the AlO₆-octahedra blocks.