Phase transitions and electrical characteristics of tungsten substituted barium titanate

Design of SrTiO3-Based Thermoelectrics by Tungsten Substitution

“…It is necessary to note that barium titanate-based compositions allow significant incorporation of tungsten even in air, without onset of secondary phases. , Easier incorporation of W 6+ in barium titanate may be explained by favorable conditions to allow an increase in ionic radius of trivalent Ti Ti ′ because Ti 4+ cations are smaller than required for the ideal tolerance factor, i.e., (r Ti + r O )/(r Ba + r O ) 1/2 < 1, and possibly also by other differences in defect chemistry, such as favorable energetics of Ti vacancies . Sintering at 1773 K and under reducing conditions was, thus, needed to obtain single-phase materials.…”

Lead palladium titanate: A room-temperature multiferroic

“…This can be rationalized by changes in the unit cell induced by doping with Pd 4+ ion, whose radius (0.615 Å [27]) is slightly larger than that of Ti 4+ (0.605Å [27]). The phenomenon of transition temperature decreasing with the substitution of larger cations for smaller cations was observed in various perovskites and related structures and the effect can be as large as a 100°C shift [30,31].…”

Influence of processing conditions on the grain growth and electrical properties of barium zirconate titanate ferroelectric ceramics

“…This is possibly due to the fact that the ionic radius of Zr +4 ion (0.87Å) is higher than that of Ti +4 ion (0.68Å) and more and more Zr +4 ions occupy Ti +4 sites on increasing the sintering temperature [17]. Moreover, the splitting of tetragonal peaks (1 0 0) and (0 0 1); (2 0 0) and (0 0 2); and (2 1 0) is observed at 2Â = 22.355 • , 45.262 • , 51.096 • respectively on increasing the sintering temperature which is indicative of the fact that the tetragonal phase grows when the sample is sintered at higher temperature [18]. Fig.…”