Ternary\nSuboxides Ti₇Ga₂O₆, Ti₃GaO, and Ti₅Ga₃O

Abstract

Single crystals of the new suboxides\nTi₇Ga₂O₆ and Ti₃GaO were\nprepared using a Bi flux.\nTi₇Ga₂O₆ has a novel monoclinic crystal\nstructure (<i>a</i> = 17.3111(8) Å, <i>b</i> = 2.97660(10) Å, <i>c</i> = 7.2563(3) Å, β\n= 105.836(2)°, space group <i>C</i>2/<i>m</i>), in which three O sites and one Ga site are separately coordinated\nby Ti atoms. Ti₃GaO crystallizes in an orthorhombic cell\n(<i>a</i> = 3.0952(2) Å, <i>b</i> = 10.6440(7)\nÅ, <i>c</i> = 8.3206(5) Å, space group <i>Cmcm</i>) with a filled-Re₃B type (anti-CaIrO₃ type or antipost-perovskite type) structure. The electrical\nresistivities of a single crystal of Ti₃GaO as measured\nin the <i>c</i>-axis direction were 1.6 × 10^–6 Ωm at 300 K and 0.15 × 10^–6 Ωm\nat 10 K. Single crystals of Ti₅Ga₃O_<i>x</i> (<i>x</i> = 1) with a filled-Mn₅Si₃ type structure (hexagonal, <i>a</i> = 7.5882(2)\nÅ, <i>c</i> = 5.30170(10) Å, space group <i>P</i>6₃/<i>mcm</i>) were also obtained.