Electric Properties of La³⁺ Doped BaTiO₃ Ceramics

Abstract

Barium titanate ceramic BaTiO₃ (BT) has been investigated extensively because of scientific interest as well as various applications to electronic devices. When pure BaTiO₃ is highly resistive at room temperature (ρ > 10¹⁰ Ωcm). However its electrical resistivity can be dramatically lowered by some dopants, like rare earth elements [1, 2]. In the present research lanthanum-doped BT ceramics described by the general formula Ba_1-x La _x Ti_1-x/4O₃, for x = 0.001 and x = 0.003, was prepared by free sintering method. The electrical properties of (BLT) materials were studied by impedance spectroscopy with a Quadtech 1920-type precision LCR meter and parameters of the phase transition were determined. The equivalent circuit method was applied to fit the experimental data. The possibility of application of La-doped BT ceramics for fabrication of piezoresistive transducers sensitive for small stress load are also discussed in the present paper.

Keywords:

• BLT
• electroceramics
• donor-doping
• impedance spectroscopy
• piezoresistivity

Acknowledgment

The present research has been supported by Polish Ministry of Education and Science from the funds for science in 2010–2013 as a research project N N507 494338.