Characteristics of (Sr1-xBax)NdFe3+ 1-τFe4+τO4-y System Heat-treated in Air

To study the physical and chemical properties, solid solutions of (Sr1-xBax)NdFe3+1-τFe4+τO4-y system with x=0.0(SBN-0),0.1(SBN-1), 0.2(SBN-2) and 0.3(SBN-3) were synthesized in air at 1,473 K and annealed in air at 1,073 K for 24 h.X-ray powder diffraction assured that the four samples had tetragonal symmetries (I4/mmm). Their lattice volumesincreased gradually with x values. Nonstoichiometric chemical formulas were formulated using the data such asτ(amount of Fe4+ ion) and y(oxygen deficiency) values using Mohr salt analysis. It was found out that all the foursamples had excessive oxygen (4-y>4.0). All the samples started to lose some of their oxygen at around 613K(TG/DTA thermal analysis). They exhibited semiconductivities in the temperature range of around 283-1173K. All the fourspecimens had sufficient tensile strength to endure the force of 19.6 N (2 kg of weights) and the conductivity values ofthe ECIAs which were painted on pieces of glass with the area of 150 mm2 (10 mm × 15 mm) and it was in the order ofECIA-0→ECIA-1→ECIA-2→ECIA-3 at a constant temperature.