The structure and microstructure of BaTiO3 nanoparticles synthesized by polymeric precursor method are correlated with the mean crystallite size and tetragonality ratio, c/a. Williamson-Hall integral breadth method is used for evaluation of microstructural quantities like, mean crystallite size and microstrain, etc. The structural evolution and the related change in properties with respect to the used method in this paper and other reported methods are tried to correlate with the tetragonality ratio, c/a. The structure of the synthesized nanoparticles is characterized with XRD, SEM, TEM and EDX analysis. Microstructural parameters of BaTiO3 nanoparticles are measured with the XRD line profile analysis.

Barium titanate (BaTiO₃) is a versatile electroceramic that finds widespread applications in making electronic devices such as Multilayer Ceramic Capacitors (MLCCs), self-controlled heaters, communication filters and piezoelectric sensors [1-5]. One of the important properties of BaTiO₃ is permittivity. Even though BaTiO₃ ceramics usually display high permittivities of more than 1000 at room temperature, there may be a strongly dependence on chemical and microstructural variations [4]. For example, Buessem et al. [6] explained the high permittivity in fine-grained BaTiO₃ ceramics in terms of an internal stress below the Curie temperature (T_c). The `grain size effect on permittivity', has been one of the most important subjects in BaTiO₃ ceramics. In addition to these reports, there are a few studies showing the change in dielectric properties of BaTiO₃ ceramics as a result of microstructural evolution of BaTiO₃ ceramics [4, 7]. Although, the bulk properties of BaTiO₃ ceramics have been widely investigated in the past, more recently, there has been a renewal of interest in nanoscale particles of BaTiO₃ because its electrical properties are strongly dependent upon the grain size and the crystalline structure [4]. High dielectric constant BaTiO₃ ceramics, with ultra-fine grains, are the need of the hour in order to obtain a thinner dielectric layer [8-10].

polymeric precursor, crystallite, tetragonality ratio, structural evolution, Barium titanate, Multilayer Ceramic Capacitors, self-controlled heaters, communication filters, piezoelectric sensors, permittivity, dielectric properties