Study of Phase Transitions in the NaNbO₃-PbSnO₃-BaSnO₃Solid Solutions

Abstract

The effect of d.c. electric field on a temperature dependence of dielectric permittivity of 0.925NaNbO 3 -0.075(Pb x Ba 1-x )SnO 3 solid solutions was investigated. The dependen-For compositions with the concentration x = 0 and x = 1 the appearance of ferroelectric and antiferroelectric phases as a result of appropriate phase transitions has confirmed. For x = 0.5 at decreasing of temperature a transition from the paraelectric to the antiferroelectric phase at first is realized, and then, at least in a part of a sample, a metastable ferroelectric state is arose.

A new, lead free, family of perovskites with a diffuse phase transition: NaNbO 3 -based solid solutions

“…4). When a small amount of FE third component is added to the given solid solution, ∆T h values usually increase [10][11][12]. At higher FE component content the ∆T h values decrease dramatically [11].…”

“…At higher FE component content the ∆T h values decrease dramatically [11]. If the temperature is stabilized in the course of cooling within the thermal hysteresis range the temporal changes in ε ′ do not exceed a few % during several hours [12]. Application of DC bias on compositions exhibiting giant ∆T h values does not change the ε ′ (T ) curve measured in the heating mode while in the course of subsequent cooling some lowering of the ε ′ (T ) maximim was observed [12,13].…”

“…If the temperature is stabilized in the course of cooling within the thermal hysteresis range the temporal changes in ε ′ do not exceed a few % during several hours [12]. Application of DC bias on compositions exhibiting giant ∆T h values does not change the ε ′ (T ) curve measured in the heating mode while in the course of subsequent cooling some lowering of the ε ′ (T ) maximim was observed [12,13]. Anomalously large values of ∆T h were observed both in the ceramics and single crystals and can serve as an experimental evidence of the fact that the given solid solution belongs to group II [7,9,11].…”