Thermal transport and high-temperature thermoelectric performance of normal and inverse ZnGa2O4 spinel structures
Materials Today Communications, vol.55, 2026 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 55
- Publication Date: 2026
- Doi Number: 10.1016/j.mtcomm.2026.115883
- Journal Name: Materials Today Communications
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Compendex, INSPEC
- Keywords: Cation inversion, Dielectric function, Elastic constants, Normal and inverse spinel, Optical properties, Phonon dispersion, Thermoelectric properties, ZnGa2O4
- Recep Tayyip Erdoğan University Affiliated: Yes
Abstract
Understanding high-temperature thermal transport in wide-band-gap oxides is essential for designing next-generation thermoelectric and thermal management systems. In this work, the thermal transport behavior and high-temperature thermoelectric performance of normal and inverse spinel ZnGa2O4 are systematically investigated using first-principles calculations combined with semi classical Boltzmann transport theory. Structural optimization was performed within the GGA-PBE framework, while electronic properties were evaluated using the modified Becke–Johnson potential to ensure reliable band-gap estimation. Special emphasis is placed on phonon-mediated heat conduction, lattice thermal conductivity, Debye temperature, and temperature-dependent transport coefficients in the range 300–1000 K, corresponding to practical industrial operating conditions. Phonon dispersion analysis confirms dynamical stability and reveals distinct vibrational features governing lattice heat transport. The inverse configuration exhibits reduced lattice thermal conductivity due to modified phonon dispersion and enhanced phonon scattering pathways induced by cation redistribution. Thermoelectric analysis indicates that cation inversion enhances electrical conductivity at elevated temperatures while maintaining moderate Seebeck coefficients, resulting in improved figure of merit (ZT) above 600 K. The combined reduction in lattice thermal conductivity and enhancement in carrier transport suggests that controlled cation engineering can be an effective strategy for optimizing ZnGa₂O₄-based materials for high-temperature waste heat recovery and thermal energy conversion systems.