Effect of temperature on grain size, phase composition, and electrical properties in the relaxor-ferroelectric-system Pb(Ni1∕3Nb2∕3)O3-Pb(Zr,Ti)O3

Abstract

Relaxor ferroelectrics near the morphotropic phase boundary were prepared by pressureless sintering at various temperatures in order to study the influence of grain size on phase composition and electrical properties. Investigations of the microstructure indicate an increase in grain size from 0.5to3.7μm when the sintering temperature is increased from 1050to1290°C. The corresponding phase composition is changed from predominantly rhombohedral for small grain sizes to more than 80% tetragonal for larger grain sizes. Low-voltage measurements of poled and unpoled samples correlate well with the x-ray diffraction results. An increase of the permittivity after poling is found for samples with a high tetragonal phase content, while samples with a predominantly rhombohedral composition show a slight decrease. The remanent polarization as well as uni- and bipolar strain increase with increasing sintering temperature by a factor larger than 2, whereas the coercive field EC remains nearly constant for all sintering conditions.

Effect of grain size on dielectric and ferroelectric properties of nanostructured Ba0.8Sr0.2TiO3 ceramics

“…As the grain size increases, the c/a ratio also increases. These results are in agreement with the previous observations of PMN-PT relaxor ferroelectric ceramics and the grain and particle size effects on microwave properties of BaTiO 3 ceramics [4,12]. Average grain sizes of the Ba 0.8 Sr 0.2 TiO 3 ferroelectric ceramics are estimated using SEM and high resolution TEM.…”

“…The average grain sizes of the present ceramics are estimated in the range of 150 nm to 300 nm after sintering, suggesting that the nanocrystalline nature is retained even after sintering at high temperature. Figure 2(ii) shows the typical TEM micrograph of the Ba 0.8 Sr 0.2 TiO 3 ferroelectric ceramics; it reveals that, the grain sizes in the range of 20-50 nm are much smaller than those reported elsewhere [3,4,12]. Such fine-grained microstructure is produced for the first time in BST ceramics and the size of these particles is comparable to crystallite sizes calculated by the XRD peak broadening.…”

Phase-formation, microstructure, and piezoelectric/dielectric properties of BiYO3-doped Pb(Zr0.53Ti0.47)O3 for piezoelectric energy harvesting devices

“…Most of the recent work reported a high transduction coefficient in the various relaxor materials doped PZT system. The doped relaxor materials generally enhanced the piezoelectric coefficients, while it abruptly lowered T c [35]. Thus, low T c limits the application fields of these materials.…”

Dielectric anomalies due to grain boundary conduction in chemically substituted BiFeO3

“…Formation of wider/bigger grains (from smaller grains) with grain boundary junctions takes place during this high temperature process. [35][36][37] On the other hand, dense morphology, large grains, and surrounded grain boundaries favor the grain boundary stimulated magneto-dielectric response near the Neel temperature, as evidenced and discussed in the section of electrical properties. 37 …”