Dielectric and Electromechanical Behaviors of PMN—PT Ceramic Samples

Abstract

The results of the investigations on (1 — x)PMN-xPT ceramic samples obtained by sol—gel (SG) technology are presented in this study. In the (1 — x)PMN-xPT samples, the temperature Tm (at which real part of dielectric permittivity reaches its maximum) increases from ~270 K for x = 0 to ~500 K for x = 0.5. At room temperature, the samples with low values of x exhibit relaxor properties, while with increasing x the transition to normal ferroelectric properties takes place. Usually 0.9PMN-0.1PT or 0.925PMN-0.075PT solid solutions are considered as boundary compositions between relaxor and ferroelectric properties at room temperature.This study presents the analysis of X-ray diffraction patterns, fracture microphotographs, electromechanical parameters, and hysteresis loops for ceramics obtained from SG PMN—PT powders densified by the hot pressing method with a composition range, x = 0—0.37.

Сегнетоэлектрические релаксорные свойства образцов системы (1-2x)BiScO-=SUB=-3-=/SUB=-· xPbTiO-=SUB=-3-=/SUB=-· xPbMg-=SUB=-1/3-=/SUB=-Nb-=SUB=-2/3-=/SUB=-O-=SUB=-3-=/SUB=- (0.30≤ x≤0.46)

“…Поскольку состав 0.5PMN · 0.5PT релаксорные свой-ства не проявляет [23], их возникновение в изучаемой системе обусловлено, очевидно, дополнительным разу-порядочением разновалентных катионов в позициях A и B перовскитной структуры, вызванным вхождением в эти позиции помимо Pb 2+ и (Ti 4+ , Mg 2+ , Nb 5+ ) Bi 3+ и Sc 3+ соответственно.…”

Technology, Physical Properties and Phase Transitions in PMN-PT-PS Ceramics

“…PMN, PT and in the next step PMN-PT specimens have been synthesized using sol-gel technology similar to the one described in the work of Jiwei [6]. Technology and properties of our PMN-PT samples have been described elsewhere [7]. The results of investigations of d.c. and a.c. conductivity are presented in [8].…”

Dielectric and Mechanical Properties of BaBi2(Nb0.99V0.01)2O9 Ceramics

“…The second part of paper is focused on dielectric properties of this interesting material. The pure BBN ceramics, as well as the modified ones by vanadium, show the frequency dependence of the dielectric response typical for relaxor ferroelectrics [7,8] i.e. the significant reduction of εε' max and shift of the corresponding temperature (T m ) towards higher values with the frequency increase.…”