Tunneled intergrowth structures in the Ga₂O₃-In₂O₃-SnO₂ system

The structures of several Ga₂O₃-In₂O₃-SnO₂ phases were investigated using high-resolution electron microscopy, X-ray diffraction, and Rietveld analysis of time-of-flight neutron diffraction data. The phases, expressed as Ga(4-4x)In(4x)Sn(n-4)O(2n-2) (n = 6 and 7-17, odd), are intergrowths between the β-gallia structure of (Ga, In)₂O₃ and the rutile structure of SnO₂. Samples prepared with n ≥ 9 crystallize in C2/m and are isostructural with intergrowths in the Ga₂O₃-TiO₂ system. Samples prepared with n = 6 and n = 7 are members of an alternative intergrowth series that crystallizes in P2/m. Both intergrowth series are similar in that their members possess 1-D tunnels along the b axis. The difference between the two series is described in terms of different crystallographic shear plane operations (CSP) on the parent rutile structure. (C) 2000 Academic Press.