Ein neues quaternäres Oxotitanat: Ba4Ti10Al2O27

A New Quaternary Oxotitanate: Ba₄Ti₁₀Al₂O₂₇ Single crystal of Ba₄Ti₁₀Al₂O₂₇ were prepared by heating oxide mixtures with NaOH flux for 20 days to 1300°C. X-ray investigations show monoclinic symmetry: a = 1973.7; b = 1134.9; c = 983.7 pm; β = 109.4°; space group C_2h³—C2/m. Ti⁴⁺/Al³⁺ occupy statistically more or less distorted octahedra, Ba²⁺ has an coordination number of 11 or 12, respectively. The complex frame work of octahedra is discussed.