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.

Artikel-ID: 100522 // This research was supported by DAAD Förderprogramme (Project-ID: 57610929) and Seed-funding of TUDa (project-ID: 40101580). The financial support of the German Science Foundation (DFG) in the Collaborative Research Centre 1548 (CRC 1548, project number 463184206) is acknowledged. AK acknowledges the support of the project CICECO - Aveiro Institute of Materials (UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020) financed by national funds through the FCT/MCTES (PIDDAC). Gabriel Constantinescu acknowledges the support of the FCT-DAAD bilateral mobility project 2021.09690.CBM, from the ‘Programme for Cooperation in Science between Portugal and Germany’, financed by the FCT.