Investigations of Structural Dielectric and Electrical Properties of Some Lead Free Tungsten Bronze Niobate Ceramics

Abstract

ABSTRACT newlineIn modern era dielectric materials have got immense attraction by researchers and scientists due to their remarkable potentiality to produce as well as operate the material as per the requirements and usefulness in various device applications. Dielectric ceramics with significant characteristics reconciled with the demand of high computing power, device fabrications, material processing technology etc. Recent years a large number of works are reported on different dielectric materials with improved properties suitable for technological applications. Dielectric constant, loss tangent, power factor, impedance, ac and dc conductivity are the major parameters that determine the functionality of the materials. Considerable research work carried out to improvise the traditional mechanization for processing, growth, fabrication along with cost and better quality of materials. Dielectric materials having ferroelectric properties procure many fascinating characteristics such as piezoelectric, pyroelectric, electro-optic and electromechanical properties distinguishing them from normal dielectric materials. Due to these special characteristics ferroelectric materials are suitable for industrial purposes such as high permittivity capacitors, piezo-transducers, actuators, ferroelectric random access memory, resonator, thermistor, sensor, light modulator etc. newlineThe factors that influence the properties of ferroelectric materials are type and proportion of substitution and synthesis route technology also the conditions for formation of the compounds. Ferroelectric materials having tungsten bronze (TB) structural families being impressive because of high dielectric constant, low loss, spontaneous polarization, better optical, pyroelectric, piezoelectric and photorefractive properties. The structure of Tungsten Bronze family is of oxygen octahedral substructure and appreciably more open than perovskite structure (ABO3) commonly written as [(A1)2(A2)4(C)4][(B1)2(B2)8]O30, with many interstices like A1,A2, B1, B2 and C. A co