Study of temperature and frequency dependant dielectric, impedance, AC resistivity, modulus spectroscopy and electromechanical coupling properties of [BaNd_0.1Ti_0.8Nb_0.1O₃]_(1-x)[Na_0.5Bi_0.5TiO₃]_x relaxor ferroelectric ceramics

Abstract

[BaNd_0.1Ti_0.8Nb_0.1O₃]_(1-x)[Na_0.5Bi_0.5TiO₃]_x ceramics with x = 0.25, 0.40, 0.60, 0.65 & 0.70 were prepared through solid-state sintering route. In the present study, temperature and frequency dependant dielectric, Impedance, AC resistivity, modulus spectroscopy and electromechanical coupling properties carried out. These materials showed modulus resonance and anti-resonance i.e. electromechanical coupling (M″ vs. frequency). From these modulus resonance and anti-resonance studies piezoelectric charge constant (d₃₃) was obtained. The values of the piezoelectric charge constant (d₃₃) are 3.34 nm V⁻¹, 6.26 nm V⁻¹, 11.58 nm V⁻¹, 14.10 nm V⁻¹ & 10.70 nm V⁻¹ for x = 0.25, 0.40, 0.60, 0.65 & 0.70, respectively. In the present study, the modulus electromechanical was studied in jig with spring which applies constant stress on the ceramic sample. The higher value of electromechanical coupling conversion in the present study may be attributed to this constant applied stress, higher temperature and polarized oxygen vacancies at the crystal lattice at these elevated temperatures (773 K & 873 K).

Keywords:

• Dielectric
• relaxor
• impedance
• AC & DC resistivity
• modulus spectroscopy
• electromechanical