Molten salt synthesized La- substituted CaTiO3 thermoelectric ceramics
Xingxing Xiao,
Saad Arif,
Jinxue Ding,
Marc Widenmeyer,
Gabriel Constantinescu,
Andrei Kovalevsky,
Hongbin Zhang,
Wenjie Xie,
Anke Weidenkaff
Affiliations
Xingxing Xiao
Materials and Resources, Department of Materials and Earth Sciences, Technical University of Darmstadt, 64287, Darmstadt, Germany
Saad Arif
Materials and Resources, Department of Materials and Earth Sciences, Technical University of Darmstadt, 64287, Darmstadt, Germany
Jinxue Ding
Materials and Resources, Department of Materials and Earth Sciences, Technical University of Darmstadt, 64287, Darmstadt, Germany
Marc Widenmeyer
Materials and Resources, Department of Materials and Earth Sciences, Technical University of Darmstadt, 64287, Darmstadt, Germany
Gabriel Constantinescu
Department of Materials and Ceramic Engineering, CICECO – Aveiro Institute of Materials, University of Aveiro, 3810-193, Aveiro, Portugal
Andrei Kovalevsky
Department of Materials and Ceramic Engineering, CICECO – Aveiro Institute of Materials, University of Aveiro, 3810-193, Aveiro, Portugal
Hongbin Zhang
Theory of Magnetic Materials, Institute of Materials Science, Technical University of Darmstadt, 64287, Darmstadt, Germany
Wenjie Xie
Materials and Resources, Department of Materials and Earth Sciences, Technical University of Darmstadt, 64287, Darmstadt, Germany; Fraunhofer Research Institution for Materials Recycling and Resource Strategies IWKS, 63755, Alzenau, Germany; Corresponding author. Materials and Resources, Department of Materials and Earth Sciences, Technical University of Darmstadt, 64287, Darmstadt, Germany.
Anke Weidenkaff
Materials and Resources, Department of Materials and Earth Sciences, Technical University of Darmstadt, 64287, Darmstadt, Germany; Fraunhofer Research Institution for Materials Recycling and Resource Strategies IWKS, 63755, Alzenau, Germany
Benefiting from molten salts as reaction media, molten salt synthesis (MSS) offers advantages such as control of local reaction conditions to tailor material characteristics, the production of uniform and homogeneous crystallites, as well as reduced energy consumption and emissions. In this study, we successfully synthesized regular polyhedral La-substituted CaTiO3 with an orthorhombic perovskite structure under molten salt conditions, utilizing a NaCl–KCl eutectic mixture at 1073 K for 6 h. The phase compositions of the prepared samples were determined through powder X-ray diffraction (XRD), and their morphologies were characterized via scanning electron microscopy (SEM). Our investigation of the thermoelectric properties reveals that the substitution of La3+ ions significantly enhances electrical conductivity and simultaneously introducing defects that substantially reduce lattice thermal conductivity. We achieved a maximum thermoelectric figure of merit (ZT) of approximately 0.27 at about 1200 K for the sample with a nominal composition of Ca0.8La0.2TiO3. This study is intended as a reference to experimentalists working in MSS for synthesizing CaTiO3-based ceramics and discloses the transport properties of La-doped CaTiO3-based ceramics.
