Dielectric and Impedance Studies of (Ba,Ca)TiO3 Ceramics Obtained from Mechanically Synthesized Powders

Kamil Feliksik; Lucjan Kozielski; Izabela Szafraniak-Wiza; Tomasz Goryczka; Małgorzata Adamczyk-Habrajska

doi:10.3390/ma12244036

Dielectric and Impedance Studies of (Ba,Ca)TiO₃ Ceramics Obtained from Mechanically Synthesized Powders

Materials (Basel). 2019 Dec 4;12(24):4036. doi: 10.3390/ma12244036.

Authors

Kamil Feliksik¹, Lucjan Kozielski¹, Izabela Szafraniak-Wiza², Tomasz Goryczka¹, Małgorzata Adamczyk-Habrajska¹

Affiliations

¹ Faculty of Science and Technology, Institute of Materials Engineering, University of Silesia, 75 Pułku Piechoty St. 1A, 41-500 Chorzów, Poland.
² Institute of Materials Science and Engineering, Poznan University of Technology, Jana Pawła II 24, 61-138 Poznań, Poland.

Abstract

Mechanochemical synthesis offers unique possibility of perovskite phase formation at ambient conditions that is very attractive (simplifies production, allows strict stoichiometry control and brings economic benefits). In this work the mechanochemical synthesis has been used for preparation ofBa_1-xCa_xTiO₃ (0.2 ≤ x ≤ 0.3) powders from simple oxides. The 20 h milled powders have been uniaxially pressed and sintered in order to get the ceramic samples. The sample morphologies have been observed by scanning electron microscopy. Dielectric and impedance studies have been performed on ceramics. The obtained results indicate that the two mechanism of doping occurred. The first one is observed for the lower calcium concentration (below 0.3) and consists of the introduction of calcium ion into the A site of the perovskite structure. The second one is observed for the higher calcium concentration (equal 0.3). In this case the calcium ions partially occupies the B site in the perovskite structure. Both cases have different influence on the final properties of the ceramics because they induce different defects.

Keywords: BCT ceramics; lead-free piezoelectric material; mechanochemical synthesis.