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Journal ArticleDOI

Abnormal Grain Growth Free Strontium Barium Niobate by Microwave Assisted Sintering

01 Sep 2015-Ferroelectrics (Taylor & Francis)-Vol. 481, Iss: 1, pp 196-205
TL;DR: In this paper, a microwave assisted sintering of strontium barium niobate (SBN) was proposed to overcome the problem of abnormal grain growth (AGG), associated duplex microstructure and pores.
Abstract: Strontium barium niobate (SBN) with the general formula SrxBa1-xNb2O6 having tetragonal tungsten bronze (TTB) structure is an exceptional and promising lead free ferroelectric material among the family of ferroelectrics. SBN exhibits ferroelectricity in a wide compositional range x = 0.32 – 0.82, compared to perovskite materials such as barium strontium titanate (BST) and barium titanate (BT), which exhibit ferroelectric phase in only one particular composition. Consequently, desired applications can be reached by tuning the Curie temperature (Tc). However, a serious problem encountered in densified SBN was the presence of an abnormal grain growth (AGG), associated duplex microstructure and pores. In the present work, these problems were successfully overcome by microwave assisted sintering. Structure, pure TTB phase analysis and lattice parameters of SBN were confirmed by X-Ray diffraction. AGG, associated duplex microstructure and pore free morphology of SBN were confirmed using scanning electron micros...
Citations
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Journal ArticleDOI
TL;DR: Ba0985Sr0015Zr010Ti090O3 (BSZT) compound is prepared using the standard solid-state reaction technique to explore for energy storage applications as mentioned in this paper.
Abstract: Ba0985Sr0015Zr010Ti090O3 (BSZT) compound is prepared using the standard solid-state reaction technique to explore for energy storage applications Samples prepared from this compound are sintered at various sintering temperatures (Ts) of 1200, 1250 and 1300 °C, respectively Influences of Ts on the structural, morphological, dielectric and ferroelectric properties are studied in detail Rietveld refinement is used on the X-ray diffraction pattern to confirm the crystal structure of the BSZT samples and each sample indicates the tetragonal phase with the P4mm space group Interestingly, with increasing Ts, the tetragonality increases up to 1250 °C, and then decreases for further increasing Ts, suggesting a transformation to the cubic structure Morphological analysis of the BSZT samples show that a dense microstructure is attained for higher Ts Temperature-dependent dielectric studies show that the degree of diffuseness increases up to 1250 °C, and then decreases for further increasing Ts, suggesting a weakening of the relaxor ferroelectric behavior A non-Debye type relaxation process in the complex impedance and the modulus spectroscopy studies confirm the significant contribution of both the grain and grain boundary to the electrical response of the studied sample The ferroelectric behaviors of the sample are explored from the polarization versus electric field hysteresis loops Ferroelectric properties are significantly improved with the Ts

5 citations

Journal ArticleDOI
01 Feb 2019-Vacuum
TL;DR: In this article, the growth of S r 0.6 B a 0.4 N b 2 O 6 (SBN60) thin films on a Pt-Si substrate has been carried out using Pulsed Laser Deposition (PLD) technique by varying the oxygen pressure from 1.33 × 10 − 3 m b a r to 26.67 × 10− 3 mb a r and at a fixed substrate temperature of 800 °C.

3 citations

Journal ArticleDOI
TL;DR: In this paper, the effects of sintering process on microstructure and dielectric constants of the Ba0.05Ca0.95TiO3, Ba 0.05Sr0.475Ca 0.475TiOO3 and Ba0Sr 0.95 TiO3 samples were examined.

3 citations

Journal ArticleDOI
TL;DR: In this article, the growth of Strontium Barium Niobate (Sr0.75 Ba0.25 Nb2 O6, SBN 75) thin films using Pulsed laser deposition (PLD) technique for possible realization of electrically tunable modulators.
Abstract: Present work reports the growth of Strontium Barium Niobate (Sr0.75 Ba0.25 Nb2 O6, SBN 75)thin films using Pulsed laser deposition (PLD) technique for possible realization of electrically tunable modulators. Structural and optical properties of grown SBN75 thin film were investigated indicating the growth of high quality polycrystalline and optically transparent. Prism coupling technique was further utilized for coupling the incident laser light λ = 633 nm with the grown SBN75 thin film. The guided EM radiation could be further coupled with the electric field for the realization of EO modulator.

1 citations

References
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Journal ArticleDOI
TL;DR: The structure of strontium barium niobate crystals SrxBa1-xNb2O6 is comprehensively studied in the whole range of the tetragonal tungsten bronze phase using both powder and single-crystal X-ray diffraction measurements and proves that the electrostrictive contribution to the thermal expansion plays an important role in strontia barium Niobate.
Abstract: The structure of strontium barium niobate crystals SrxBa1 − xNb2O6 is comprehensively studied in the whole range of the tetragonal tungsten bronze phase (x = 0.32–0.82) using both powder and single-crystal X-ray diffraction measurements. Unit-cell parameters, density, site-occupancy factors and interionic distances show an explicit composition dependence which can be consistently explained using simple model calculations. The temperature dependence of the unit-cell parameters exhibits a remarkable anisotropy in a broad temperature region below the phase transition temperature. This proves that the electrostrictive contribution to the thermal expansion plays an important role in strontium barium niobate.

104 citations

Journal ArticleDOI
TL;DR: In this article, the temperature dependence of spontaneous polarization in strontium-barium-niobate single crystals with varying Sr/Ba ratio was investigated and the temperature of the relaxor phase transition was determined from the inflexion point of the curve of the ferroelectric polarization versus temperature.
Abstract: The temperature dependence of the spontaneous polarization in strontium–barium–niobate single crystals with varying Sr/Ba ratio is presented. The temperature of the relaxor phase-transition is determined from the inflexion point of the curve of the ferroelectric polarization versus temperature. The influence of the Sr/Ba ratio in the crystal on the transition temperature is discussed within an effective field approach. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

55 citations


"Abnormal Grain Growth Free Strontiu..." refers background in this paper

  • ...ions smaller than Ba ions within the open TTB crystal structure gives rise to enhanced polar disorder which would increase RFs and thus decrease TC [20, 21]....

    [...]

Journal ArticleDOI
TL;DR: In this paper, the phase structure, microstructure, dielectric, ferroelectric and pyroelectric properties of obtained ceramics were systematically investigated and it was shown that SBN ceramic was a relaxor with strong diffuse phase transition and weak frequency dispersion.

49 citations


"Abnormal Grain Growth Free Strontiu..." refers background in this paper

  • ...ions smaller than Ba ions within the open TTB crystal structure gives rise to enhanced polar disorder which would increase RFs and thus decrease TC [20, 21]....

    [...]

Journal ArticleDOI
TL;DR: In this paper, the effect of presintering in controlling grain growth is discussed, and a mechanism for abnormal grain growth in Sr0.6Ba0.4Nb2O6 (SBN40) ceramics is proposed.
Abstract: Ceramics of Sr0.6Ba0.4Nb2O6 (SBN40) were prepared by the conventional mixed oxide route. Sintering at temperatures ≥ 1260 °C led to rapid, non-uniform grain growth and a duplex microstructure. Presintering at 1250 °C followed by higher temperature sintering (1350–1450 °C) controlled grain growth. Rapid cooling from 1450 °C froze-in second phases at grain boundaries. Scanning electron microscopy and transmission electron microscopy showed that the resulting grain-boundary phases were Nb2O5-rich and BaO-deficient, having low liquid-formation temperatures. In contrast, SBN40 ceramics prepared with excess BaO and a deficiency of Nb2O5 showed no enhancement of grain growth at the highest temperature. Sintering behaviour and microstructural development provide evidence for the existence of a liquid phase which assists abnormal grain growth. The effect of presintering in controlling grain growth is discussed, and a mechanism for abnormal grain growth in Sr0.6Ba0.4Nb2O6 (SBN40) ceramics is proposed. © 1998 Chapman & Hall

46 citations