Phase Relationships and Physical Properties of Homologous Compounds in the Zinc Oxide‐Indium Oxide System

Abstract

Equilibrium phase relationships in the ZnO‐In 2 O 3 system were determined between 1100° and 1400°C using solid‐state reaction techniques and X‐ray diffractometry. In addition to ZnO and In 2 O 3 , nine homologous compounds, Zn k In 2 O k +3 (where k = 3, 4, 5, 6, 7, 9, 11, 13, and 15), were observed. Electrical conductivity and diffuse reflectance of the k = 3, 4, 5, 7 and 11 members were measured before and after annealing at 400°C for 1 h under forming gas (4% 2 ‐96% N 2 ). Room‐temperature conductivity increased as k decreased, because of increased carrier concentration as well as increased mobility. In general, transparency in the wavelength range of 450‐900 nm increased as k increased. Reduction in forming gas resulted in increased conductivity and reduced transparency for all compounds measured. The highest room‐temperature conductivity measured, 270 S/cm, was that of reduced Zn 3 In 2 O 6 .