Synthesis and thermoelectric properties of Ba₂TiFeO₆ double perovskite with insight into the crystal structure

Abstract

Here we report the development of environment-friendly, non-toxic, single-phase Ba₂TiFeO₆ (BTF) double perovskite fabricated by solid-state synthesis route to evaluate its thermoelectric properties. XRD patterns and SEM micrographs confirmed phase purity and dense microstructure of ceramic sample. The crystal structure of BTF ceramic was confirmed to be hexagonal with P6₃/mmc space group by Rietveld Refinement of powder XRD data. Conduction mechanism of BTF double perovskite was analyzed by small polaron hopping and variable range hopping in correlation with the defect chemistry of this complex oxide. The maximum thermopower 412 µV/K was obtained at 1073 K in this material. The complex plane impedance spectroscopic analysis showed the disappearance of resistance contribution from grain boundaries and very negligible resistance due to grains above 400 K making it highly conductive.

KEYWORDS:

• Thermoelectric
• double perovskite
• Ba₂FeTiO₆
• oxides
• Rietveld refinement
• crystal structure

Additional information

Funding

This work is supported by the grant from Science and Engineering Research Board, DST (SERB-DST), India (Grant No: SB/S3/ME/008/2015).