Structural, dielectric and electrical properties of bismuth magnesium tantalate electronic system

Abstract

Abstract The lead-free dielectric compound Bi(Mg2/3Ta1/3)O3 (BMT) has been synthesized at high temperature by a low-cost solid-state method. The X-ray diffraction (XRD) technique reveals that the fabricated sample has an orthorhombic crystal system. The scanning electron microscope (SEM) image displays the uniform distribution of grains on the surface of the specimen. The dielectric parameters (permittivity (er), and loss tangent (tan δ) are studied over a wide range of temperature (150–500 °C) and frequency (1 kHz–1 MHz). The temperature dependent conductivity plot follows Universal Johnson's power law. The complex impedance and modulus spectrum illustrate the electrical behavior of the compound at various frequency and temperature. The Nyquist spectra show the presence of the effect of grain and grain boundary in the synthesized compound. The grain resistance value declines with the rise in temperature that shows the presence of a negative temperature coefficient (NTCR) behavior in the compound. The complex modulus spectra display the occurrence of the conduction mechanism in the specimen. The reported compound has a relative dielectric constant and loss of 22 × 103 and 1.8 respectively at 1 kHz frequency and 500 °C, thus becoming an efficient applicant for dielectric applications that can operate at higher temperatures.