The Electrical and Thermal Transport Properties of La-Doped SrTiO3 with Sc2O3 Composite

Donor-doped strontium titanate (SrTiO3) is one of the most promising n-type oxide thermoelectric materials. Routine doping of La at Sr site can change the charge scattering mechanism, and meanwhile can significantly increase the power factor in the temperature range of 423–773 K. In addition, the introduction of Sc partially substitutes Sr, thus further increasing the electron concentration and optimizing the electrical transport properties. Moreover, the excess Sc in the form of Sc2O3 composite suppresses multifrequency phonon transport, leading to low thermal conductivity of κ = 3.78 W·m−1·K−1 at 773 K for sample Sr0.88La0.06Sc0.06TiO3 with the highest doping content. Thus, the thermoelectric performance of SrTiO3 can be significantly enhanced by synergistic optimization of electrical transport and thermal transport properties via cation doping and composite engineering.

Challenges in Improving Performance of Oxide Thermoelectrics Using Defect Engineering

Oxide thermoelectric materials are considered promising for high-temperature thermoelectric applications in terms of low cost, temperature stability, reversible reaction, and so on. Oxide materials have been intensively studied to suppress the defects and electronic charge carriers for many electronic device applications, but the studies with a high concentration of defects are limited. It desires to improve thermoelectric performance by enhancing its charge transport and lowering its lattice thermal conductivity. For this purpose, here, we modified the stoichiometry of cation and anion vacancies in two different systems to regulate the carrier concentration and explored their thermoelectric properties. Both cation and anion vacancies act as a donor of charge carriers and act as phonon scattering centers, decoupling the electrical conductivity and thermal conductivity.

Review on texturization effects in thermoelectric oxides

Sustainable energy sources and energy-harvesting technologies have been researched for decades. Thermoelectric conversion is currently one of the primary foci in this area. Thermoelectric research has been concentrated into two parts—(i) strategies to enhance the efficiency of existing thermoelectric materials and (ii) development of new materials with promising thermoelectric parameters. Although such strategies have led to the improvement of thermoelectric non-oxide-based materials, the limitations possessed by them does not allow to be used at high temperatures. Due to the same reason, oxide-based materials have gained much attention. Here, we discuss about the oxide thermoelectric materials in detail and the effect of texturization on their morphology and transport properties. There is a lot of scope available for such class of materials for high-temperature applications.

Pembentukan Fasa Co3O4 Dengan Metoda Dekomposisi CoCO3 Menggunakan Sinar Diffraksi

Experiments have been carried out to obtain the decomposition of cobalt carbonate cobalt oxide to be used as raw material for the manufacture of calcium cobalt oxide thermoelectric materials. The experiments were performed by heating cobalt carbonate powder material (CoCO3) from Kanto Chemical with a temperature of 1000°C. Heating aims to obtain Co3O4 phase. Co3O4 phase is what will be used in the manufacture of thermoelectric materials based on the phase diagram of the system Ca-Co-O. The results of X-ray diffraction CoCO3 materials are heated to 1000°C showed that Co3O4 phase has been formed. Analysis quantitative diffraction pattern shows the diffraction peaks are the property throughout the Co3O4 phase. The crystal structure of Co3O4 is Face Centered Cubic (FCC) with space group F d -3 m. Lattice parameters of the diffraction pattern is the result of smoothing a = 8.0838 Å.