0556549 - ÚFP 2023 RIV CH eng J - Journal Article
Ctibor, Pavel - Straka, L. - Lukáč, František - Sedláček, J.
Stability Study of Dielectric Properties of Plasma-Sprayed BaTiO3.
Coatings. Roč. 12, č. 3 (2022), č. článku 355. ISSN 2079-6412. E-ISSN 2079-6412
Institutional support: RVO:61389021
Keywords : barium-titanate * temperature stability * spectroscopy * ceramics * plasma spraying * electrical properties * dielectric ceramics * annealing
OECD category: Materials engineering
Impact factor: 3.4, year: 2022 ; AIS: 0.439, rok: 2022
Method of publishing: Open access
Result website:
https://www.mdpi.com/2079-6412/12/3/355DOI: https://doi.org/10.3390/coatings12030355

Barium titanate coatings were, for the first time, sprayed by a high feed-rate plasma torch with water stabilization of the plasma. Two power levels of the torch were applied for spraying to cover steel substrates. Various substrate preheating levels from 125 degrees C to 377 degrees C were used to modify cooling conditions. Microstructure and phase composition including crystallinity quantification were observed. Dielectric measurements proved that the relative permittivity between 300 and 400 coatings is too temperature sensitive over 170 degrees C but fits the requirements of the EIA temperature coefficient between room temperature and 170 degrees C. Simultaneously, the loss tangent remains rather low, between 0.02 and 0.07, in a broad range of temperatures and frequencies. Annealing was performed in air to heal the oxygen deficiency, but only modified the microstructure insignificantly. The dielectric properties of as-sprayed and annealed samples were discussed, with the main finding that the temperature coefficient of permittivity was improved by annealing. This study contributes to the search for the suitability of plasma-sprayed BaTiO3 coatings for application in the electrical industry, namely by the optimization of conditions for high feed-rate spraying.
Permanent Link: https://hdl.handle.net/11104/0341086