Formation and structural refinements of tunneled intergrowth phases in the Ga2O3–In2O3–SnO2–TiO2 system

Over 100 samples were prepared as (Ga,In)4(Sn,Ti)n−4O2n−2, n=6, 7, and 9 by solid-state reaction at 1400 °C and characterized by X-ray diffraction. Nominally phase-pure beta-gallia–rutile intergrowths were observed in samples prepared with n=9 (0.17⩽x⩽0.35 and 0⩽y⩽0.4) as well as in a few samples prepared with n=6 and 7. Rietveld analysis of neutron time-of-flight powder diffraction data were conducted for three phase-pure samples. The n=6 phase Ga3.24In0.76Sn1.6Ti0.4O10 is monoclinic, P2/m, with Z=2 and a=11.5934(3) Å, b=3.12529(9) Å, c=10.6549(3) Å, β=99.146(1)°. The n=7 phase Ga3.24In0.76Sn2.4Ti0.6O12 is monoclinic, C2/m, with Z=2 and a=14.2644(1) Å, b=3.12751(2) Å, c=10.6251(8) Å, β=108.405(1)°. The n=9 phase Ga3.16In0.84Sn4TiO16 is monoclinic, C2/m, with Z=2 a=18.1754(2) Å, b=3.13388(3) Å, c=10.60671(9) Å, β=102.657(1)°. All of the structures are similar in that they possess distorted hexagonal tunnels parallel to the [010] vector.