Influences of crystal structure, microstructure and adsorbed CO2 on dielectric properties of Ba2YbSbO6-BaCO3 formed by mechanical activation of Ba2YbSbO6

Abstract

Herein, we have reported the structural, microstructural, thermal, optical and temperature dependent dielectric properties (between 40 Hz and 5 MHz) of Ba2YbSbO6 (BYSB) synthesized by solid state ceramic method and a nanocomposite of Ba2YbSbO6-BaCO3 (BYSN). The samples are characterized by XRD, FESEM, EDS, FTIR and Raman spectroscopy. The nanosized Ba2YbSbO6 prepared by ball milling of BYSB adsorbs atmospheric CO2 leading to the formation of BYSN. The dielectric behaviours of the samples have been examined in the framework of dielectric permittivity, electric modulus and conductivity formalisms. The samples exhibit non-Debye type relaxation governed by polaron hopping. BYSN exhibits better dielectric behaviour than BYSB. It has been shown that crystal structure, grain size, grain boundary contribution and surface adsorbed CO2 strongly influence the dielectric relaxation dynamics and conduction mechanism of the samples. The dielectric response of these samples is comparable to their analogues counterparts used for fabrication of radio frequency devices.