2016/07/25 by Denis Mušić, Richard W. Geyer, Marcus Hans · 1 citation
Materials Science · Engineering · Chemistry · #Advanced Thermoelectric Materials and Devices #Electronic and Structural Properties of Oxides #Semiconductor materials and devices #Seebeck coefficient #Thermoelectric effect #Materials science #Thermoelectric materials #Amorphous solid #Electrical resistivity and conductivity #Condensed matter physics #Oxide #Density functional theory #Thermodynamics #Thermal conductivity #Composite material #Metallurgy #Chemistry #Computational chemistry #Physics #Crystallography
paper · doi:10.1063/1.4959608
openalex publication_date 2016/07/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
To increase the thermoelectric efficiency and reduce the thermal fatigue upon cyclic heat loading, alloying of amorphous NbO2 with all 3d and 5d transition metals has systematically been investigated using density functional theory. It was found that Ta fulfills the key design criteria, namely, enhancement of the Seebeck coefficient and positive Cauchy pressure (ductility gauge). These quantum mechanical predictions were validated by assessing the thermoelectric and elastic properties on combinatorial thin films, which is a high-throughput approach. The maximum power factor is 2813 μW m−1 K−2 for the Ta/Nb ratio of 0.25, which is a hundredfold increment compared to pure NbO2 and exceeds many oxide thermoelectrics. Based on the elasticity measurements, the consistency between theory and experiment for the Cauchy pressure was attained within 2%. On the basis of the electronic structure analysis, these configurations can be perceived as metallic, which is consistent with low electrical resistivity and ductile behavior. Furthermore, a pronounced quantum confinement effect occurs, which is identified as the physical origin for the Seebeck coefficient enhancement.