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Influence of vanadium dopping on dielectric properties of barium titanate ceramics

Stanuch K.

Czasopismo Techniczne. Chemia

2014

R. 111, z. 1-Ch

109--116

The purpose of this article is to present the impact of vanadium substitution on the dielectric properties of barium titanate. Doping barium titanate (BaTiO3) by different ions such as vanadium V5+ provides the possibility of changing its dielectric properties. SEM images indicate the differences between pure BaTiO3 (BT) and Ba(Ti0.98V0.02)O3 (BTV2). Using dielectric measurements, the Curie temperatures (Tc) were calculated – they were found to be equal to 403 K and 396 K, respectively. Moreover, for BTV2 the Curie - Weiss temperature and the Curie constant (C) were determined (T0 = 368 K and C = 1.46 ×105 K, respectively).

Domieszkowanie tytanianu baru BaTiO3 (BT) jonami innych pierwiastków, jak wanad V5+, umożliwia zmiany jego właściwości dielektrycznych. Obserwacje z wykorzystaniem SEM wskazują na różnice w strukturze mikrokrystalicznej między BaTiO3 (BT) a Ba(Ti0.98V0.02)O3 (BTV2). Z pomiarów dielektrycznych wyznaczono temperaturę Curie (Tc). Dla BT wynosi ona 403 K, a dla BTV2 396 K. Dla BTV2 określono również temperaturę Curie-Weissa oraz stałą Curie (T0 = 368 K and C = 1.46 ×105 K).

Dielectric spectroscopy study of Ba0.98Na0.02Ti0.98Nb0.02O3 ceramic

Bąk W., Gabryś M., Kajtoch C., Stanuch K., Starzyk F.

Archives of Materials Science and Engineering

2009

Vol. 39, nr 2

107-110

Purpose: The purpose of this work was to investigate dielectric properties of new ceramic solid solution Ba0.98Na0.02Ti0.98Nb0.02O3 (BNTN2) within the temperature range 153 K - 473 K. Design/methodology/approach: The dielectric spectroscopy method was applied to measure frequency and temperature dependence of complex dielectric permittivity, complex admittance, phase angle. The frequency dependence of ac conductivity at constant temperature was analysed as well as reciprocal permittivity and dielectric modulus as functions of temperature and frequency were compared. The Curie-Weiss rule and its generalized formula were applied in outcomes analysis. Findings: The ferroelectric - paraelectric (FE - PE) phase transition occurring in BNTN2 was found as having diffusive nature. In the paraelectric phase at about 400 K the diffusivity of transition step is correlated with the same kind of transition in BaTiO3 (BT) (transition of FE - PE type) and with structural transition occurring in NaNbO3 (NN). Within the temperature range below Tm = 308 K, dependences of dielectric properties of BNTN2 ceramic on temperature and frequency was found as having relaxor type of behaviour. Research limitations/implications: The confirmations of achieved findings will be possible by more precise BNTN2 structure determination by means X-ray diffraction. Also closer explanation of FE - PE phase transition can be performed by dielectric measurements within broader frequency range up to 1.8 GHz ( diffusive versus relaxor character of transition). Originality/value: The new solid solution of BNTN2 was prepared. The structure of this material was characterized as dielectrically active and having FE - PE phase transition which was described.