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.

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. [ABSTRACT FROM AUTHOR]