Phase stabilization in plasma sprayed BaTiO3

Abstract

This paper presents a comparison of properties of BaTiO 3 ceramics prepared by two different production methods: gas-stabilized plasma spraying (GSP) and spark plasma sintering (SPS). Samples of both materials were evaluated by various techniques, the goal being to detect the Curie temperature of the ferroelectric transformation between the tetragonal and the cubic phase. All tests, resonant ultrasound spectroscopy, dielectric measurements, differential scanning calorimetry and temperature-resolved X-ray diffraction (XRD), used in combination, proved the absence of this transformation in the case of GSP coating up to 500 1C. Similarly, the tetragonal-toorthorhombic transition temperature is shifted downwards, this transition probably taking place in a small fraction of the volume of coating. The SPS samples exhibit several anomalies, such as a strong anisotropy of relative permittivity, but their phase transformations were detected in the usual temperature ranges.

Characterization of mechanical properties of barium titanate ceramics with different grain sizes

“…The applicability of BaTiO 3 piezoelectric material is limited to the temperature range of stability of the polar ferroelectric phase; i.e. between approximately 5 • C (the tetragonal-to-orthorhombic transition) and 120 • C (the cubic-to-tetragonal transition) [8]. The frequency response of resonant devices may be disturbed by differences in the elastic constants of piezoelectric ceramics.…”

“…structure that consists of corner-linked octahedral oxygen containing Ti 4+ , with Ba 2+ [8]. In the temperature interval between 5 • C and 120 • C, BaTiO 3 has a tetragonal polar ferroelectric phase [9].…”

Dielectric properties and vacancy‐like defects in plasma‐sprayed barium titanate

“…Striking difference in color of coatings indicates that torch type and torch settings allow varying the character of BaTiO 3 in a broad range. Obtaining of dielectric properties suitable for electrical industry just by spraying without any thermal posttreatment was, however, described as very difficult …”

Calcium titanate (CaTiO 3 ) dielectrics prepared by plasma spray and post-deposition thermal treatment

“…Results show that defects in BaTiO 3 coatings prepared by supersonic plasma spray reduce the piezoelectric effect [8]. Dielectric properties of plasma sprayed BaTiO 3 were investigated as well [9]. High relative permittivity and high loss factor were observed.…”