| Abstract Scope |
Oxide-based thermoelectric materials encounter difficulties due to their inadequate electrical conductivity, while achieving low thermal conductivity remains a challenge because of their inherently low phonon mean free path (~1nm). Here, we have adopted a two-step strategy to address these issues in oxides. Firstly, high entropy oxide (HEO) containing multicationic species has been synthesized, which induces mass fluctuation and lattice disorders within the crystal to generate high orders of phonon scattering sites, inherently reducing lattice thermal conductivity (< 1 W/mK). Thereafter, a nanocomposite approach with highly conducting carbon allotrope has been adopted. The nanocomposite of HEO with a carbon allotrope synergistically enhances electrical transport and diminishes lattice thermal conductivity. Structural and morphological characterization reveals a single-phase solid solution of HEOs and highly dense microstructure with a homogeneous distribution of constituent elements. Thermoelectric parameters such as thermopower, electrical transport, and thermal transport have been investigated thoroughly in the temperature range of 323-1023K. |