Utilizing a unified structure model in (3 + 1)‐dimensional superspace to identify a homologous phase (Ga1−αAlα)2O3(ZnO)m in ZnO‐based thermoelectric composites

• Published in: Journal of applied crystallography Vol. 53; no. 6; pp. 1542 - 1549
• Main Authors: Michiue, Yuichi, Son, Hyoung-Won, Mori, Takao
• Format: Journal Article
• Language: English
• Published: 5 Abbey Square, Chester, Cheshire CH1 2HU, England International Union of Crystallography 01.12.2020; Blackwell Publishing Ltd
• Subjects: (3 + 1)‐dimensional superspace; Aluminum oxide; Composite materials; Electrical conductivity; Electrical resistivity; Gallium oxides; homologous compounds; Homology; long‐period structures; Sintering (powder metallurgy); Thermal conductivity; thermoelectric material; Thermoelectric materials; Wurtzite; Zinc oxide
• ISSN: 1600-5767; 0021-8898; 1600-5767
• DOI: 10.1107/S1600576720013898

A unified structure model in (3 + 1)‐dimensional superspace proved suitable for identification of a homologous phase (Ga1−αAlα)2O3(ZnO)m by the profile fitting of powder X‐ray diffraction intensities for thermoelectric composite materials in the pseudoternary system ZnO–Al2O3–Ga2O3. A homologous compound of the phase parameter m ≃ 37 was found to coexist with (Al,Ga)‐doped ZnO in samples sintered at 1723 K in air. The thermoelectric properties of the composite materials were closely related to the phase fractions. The higher the phase fraction of (Al,Ga)‐doped ZnO with the wurtzite structure, the higher the electrical conductivity. On the other hand, the homologous compound with the long‐period structure was effective in lowering the thermal conductivity of the materials. A homologous compound (Ga1−αAlα)2O3(ZnO)m of a long‐period structure in thermoelectric composite materials was analysed by a unified structure model in (3 + 1)‐dimensional superspace.