Sol-gel derived Ba(Fe, Ti)O3 ferroelectric materials for infrared sensors

Abstract

In this article we report the development of Fe modified BaTiO3 using sol-gel technique and present results of structural and dielectric studies to establish its suitability for pyroelectric sensor applications. Fine powders of Fe modified BaTiO3 were prepared by sol-gel process using barium acetate, iron isopropoxide, and titanium isopropoxide. X-ray structural analyses of the BaTiO3 with different proportion of Fe ion suggest the formation of single-phase compounds having tetragonal structure at a relatively low temperature around 750 °C for 4 h. The particle size of the powder was found to be in nm range. The sintering temperature of 1250 °C for the above calcined powder was considerably lower than the powders made by the conventional methods. The ferroelectric to paraelectric phase transition of Ba(Fe, Ti)O3 ceramics was studied using the dielectric measurement. The value of dielectric constant for Fe modified BaTiO3 was found to be lower than pure BaTiO3 and the transition temperature shifted towards the lower temperature side with an increase in Fe ion concentration. A combination of low dielectric constant and a low transition temperature makes Fe modified BaTiO3 materials attractive for room temperature pyroelectric sensor applications.