Dielectric behavior of lead iron tantalate - lead titanate ceramics

D. Szwagierczak; J. Kulawik; B. Gröger

doi:doi:10.1051/jp4:2005128021

Numéro		J. Phys. IV France Volume 128, September 2005


Page(s)		133 - 137
DOI		https://doi.org/10.1051/jp4:2005128021

J. Phys. IV France 128 (2005) 133-137
DOI: 10.1051/jp4:2005128021

Dielectric behavior of lead iron tantalate - lead titanate ceramics

D. Szwagierczak, J. Kulawik and B. Gröger

Institute of Electron Technology, Cracow Division, Cracow, Poland

Abstract
Dielectric properties of complex perovskite Pb(Fe_1/2Ta_1/2)O₃ (PFT) and its solid solutions with normal ferroelectric PbTiO₃ (PT) were studied. The addition of 5 - 25 mol % of PbTiO₃ was used to shift upwards the temperature of the ferroelectric-paraelectric transition of pure PFT. Dielectric permittivity and dissipation factor of the ceramics were determined in the temperature range from -55 to 550 $^{\circ}$ C at frequencies 10 Hz - 1 MHz. Dc resistivities of the samples were measured in the temperature range 20 - 500 $^{\circ}$ C. The PFT-based ceramics sintered at 1050 $^{\circ}$ C showed a relatively high dielectric permittivity (3000 - 5700 at Curie temperature) and a high resistivity (10¹¹ - 10 $^{13}\,\Omega$ cm at 20 $^{\circ}$ C). Two broad maxima in the dielectric permittivity versus temperature plots were observed at a given frequency. The location of the first one, corresponding to the ferroelectric - paraelectric transition, changed from -30 $^{\circ}$ C for pure PFT to 80 $^{\circ}$ C for 0.75PFT-0.25PT ceramics. The second maximum, related to dielectric relaxation, occurred at higher temperatures in the range 200 - 500 $^{\circ}$ C and was strongly dependent on frequency and the content of dopants.