A study of the effect of cerium ion doping concentration on the structural, electrical, and thermoelectric properties of CaMnO3 nanoparticles

Universally, energy loss in the form of heat is predominant and this heat is irrecoverable waste heat that leads to global warming. Clean, green, eco-friendly, cost-effective, and renewable energy sources are the possible solutions for this energy crisis and global warming issues. Thermoelectric power generation is a promising technology by converting this irrecoverable waste heat directly into electricity without any greenhouse gas emission. Nanostructured CaMnO3 at various cerium concentrations have been successfully prepared by sol–gel hydrothermal method followed by annealing and sintering. Pure and doped samples were systematically characterized by DSC, powder XRD, RAMAN, SEM with EDAX and FTIR spectroscopy. Electrical and thermoelectrical measurements were carried out on the sintered pellets. The XRD analyses confirmed the formation of orthorhombic perovskite structure for all the samples and the average particle size lies in the range of 50–60 nm. FTIR analysis shows the presence of CaMnO3 nanoparticles without any impurities. The temperature dependence of physical properties was performed and analyzed between room temperature and 600 °C. Electrical resistivity strongly depends on the nature of substituent ions and negative values indicate that the electrons are major charge carriers. Large Seebeck coefficient value and high-power factor make Ca1−x Ce x MnO3 an efficient thermoelectric material for energy storage applications.