Ternary Suboxides Ti₇Ga₂O₆, Ti₃GaO, and Ti₅Ga₃O

Abstract

Single crystals of the new suboxides Ti₇Ga₂O₆ and Ti₃GaO were prepared using a Bi flux. Ti₇Ga₂O₆ has a novel monoclinic crystal structure ( a = 17.3111(8) Å, b = 2.97660(10) Å, c = 7.2563(3) Å, β = 105.836(2)°, space group C2/ m), in which three O sites and one Ga site are separately coordinated by Ti atoms. Ti₃GaO crystallizes in an orthorhombic cell ( a = 3.0952(2) Å, b = 10.6440(7) Å, c = 8.3206(5) Å, space group Cmcm) with a filled-Re₃B type (anti-CaIrO₃ type or antipost-perovskite type) structure. The electrical resistivities of a single crystal of Ti₃GaO as measured in the c-axis direction were 1.6 × 10^-6 Ωm at 300 K and 0.15 × 10^-6 Ωm at 10 K. Single crystals of Ti₅Ga₃O _x ( x = 1) with a filled-Mn₅Si₃ type structure (hexagonal, a = 7.5882(2) Å, c = 5.30170(10) Å, space group P6₃/ mcm) were also obtained.