A Comparative Study Of Electrical Properties Of Some Rare Earth Based Tungsten Bronze Ceramics

¹Department of Physics, Betnoti College Betnoti, Mayurbhanj, Odisha, India

²Department of Physics ITER, Bhubaneswar, Odisha, India

Adv. Mater. Lett., 2014, 5 (2), pp 96-99

DOI: 10.5185/amlett.2013.fdm.47

Publication Date (Web): Jan 27, 2014

Copyright © IAAM-VBRI Press

E-mail: banabihari4u@gmail.com

Abstract

The advent of nanoscience & technology have completely changed the orientation/direction of studies of eco-friendly (lead-free) materials bringing them at the forefront of scientific developments with considerably enhanced physical properties suitable for a wide variety of challenging applications. Barium based ferroelectric materials have gained much importance due to their vast applications as they possess high dielectric constant, non-linear spontaneous polarization, negative temperature coefficient of resistance behavior etc.. All these characteristics stimulated the researchers to replace toxic and hazardous lead based materials by barium based TB materials from industry. Our present research work deals with the synthesis of polycrystalline samples of Ba₂Sr₃RTi₃V₇O₃₀ (R = Gd, Sm) by a high temperature solid state reaction technique and a comparative study of the electrical properties of the samples. Preliminary structural (XRD) analyses of these compounds show the formation of single-phase orthorhombic structures at room temperature having average crystallite size of the order of some nanometer for both the compounds. The electrical properties for both the samples are studied in a wide range of temperature (30–500^oC) and frequency (100Hz-1MHz). The dielectric properties suggest that both the compounds have undergone ferroelectric-paraelectric phase transition well above the room temperatures (i.e., 230 and 313⁰C for R= Sm and Gd respectively at frequency 100 kHz).The bulk resistance of the materials exhibits negative temperature coefficient of resistance behavior as observed in semiconductors.

Keywords

Ceramics, X-ray diffraction, electric properties