Zn2+ in-situ substitution behavior during the formation of BaTiO3 coatings from plasma-sprayed powders collected in liquid nitrogen. (April 2018)

• Record Type: Journal Article
• Authors: Liu, Zhe; Xing, Zhiguo; Wang, Haidou; Xue, Zifan; Chen, Shuying; Cui, Xiufang; Jin, Guo
• Is Part Of: Journal of physics and chemistry of solids. Volume 115(2018)
• Page Start: 208
• Page End: 214
• Publication Date: 2018-04
• Subjects: Air plasma spray -- BaTiO3 -- Dielectric performance -- Liquid nitrogen -- ZnO; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2017.12.049
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: The dielectric performance of BaTiO3 ceramic coatings is enhanced significantly by the addition of ZnO. In this study, the maximum relative permittivity value (εr ≈ 923) was measured in BaTiO3 coatings with ZnO added at 6 wt%. The Curie temperature (Tc ) was in the range of 111 °C–121 °C for all of the ZnO-modified BaTiO3 coatings. Tc shifted to low temperatures as the ZnO content increased. Detailed analyses were performed to determine the phase composition and optical band gaps of powders collected in liquid nitrogen, which showed that the Zn 2+ ions were incorporated into the BaTiO3 lattice where they substituted into the Ti 4+ sites, and the composite powders (BaTiO3 + 6 wt% ZnO) tolerated high temperatures in the plasma beam. In addition, some residual Zn accumulated in the grain boundary in the form of ZnO. X-ray diffraction and Raman spectroscopy showed that the substitution led to changes in the compositional and structural properties. The red shift in the optical band gap of BaTiO3 indicated that the Z n T i ' ' defects caused by the dopants acted as carriers in the doped BaTiO3 coatings. Highlights: Plasma spraying used to dope BaTiO3 with a low concentration of ZnO. Zn-doped BaTiO3 ceramic powders collected in liquid nitrogen. Transition mechanism analyzed based on the phase composition and chemical defects.