Effect of the Strontium:Barium Ratio and Atmosphere on the Sintering Behavior of Strontium Barium Niobate

Abstract

The sintering behavior of Sr x Ba 1−x Nb 2 O 6 (SBN) (x = 0.5, 0.6, and 0.7) was studied. The densification rate increased and the evaluated activation energy of SBN decreased as the Sr:Ba molar ratio increased. Also, when SBN50 (SBN where x = 0.5) was sintered at <1300°C, the densification rate decreased as the oxygen partial pressure increased, and, at 1300°C, the oxygen partial pressure had insignificant influence on the densification. The relationship of sintering behavior and structure of SBN has been discussed, and the niobium ion was suggested as being the ratelimiting species when sintering SBN.

Kinetics of the Initial Stage of Sintering from Shrinkage Data: Simultaneous Determination of Activation Energy and Kinetic Model from a Single Nonisothermal Experiment

“…This method has been applied to the sintering of several materials such as pure and doped alumina, 7-9 cerium(III) sulfide, 10 silver film, 11 and strontium barium niobate. 12 In addition, Ozawa 13 and Doyle 14 plots have also been utilized for the kinetic analysis of the sintering process of TiO 2 15 and Si 3 N 4 . 16 -18 A method in which the shrinkage-rate data are collected at the same temperature from a series of curves obtained at different heating rates has allowed the calculation of the reaction order in the sintering of ceramic-filled glasses.…”

Defects, Structure Changes, and the Effect of Random Fields on the Displacement of Off‐Center Ions in Sr0.5Ba0.5Nb2O6 Doped with Combinations of Ce and Cr

“…The defect reactions of undoped and Cr-doped SBN50 had been determined via the study of the sintering behavior. 34,35 However, the conclusion drawn previously concerning the charge-compensating defect of Ce-doped SBN50 36 was misinterpreted and needs to be reassessed. In this investigation, the samples have been carefully prepared to assure that the dopants have completely dissolved in SBN50 without the presence of second phases, as evidenced in Fig.…”

“…2(a)), the most probable charge-compensating defect of Ce dopant would be the niobium vacancy because the niobium ion has been proven to be the rate-limiting species during sintering SBN50 ceramics. 34 Regarding the codoping (Ce,Cr), because Ce is a donor and Cr is an acceptor, the self-compensation would be the most plausible defect reaction than the creation of the vacancies in the light of its lower formation energy. Cr dopant had been demonstrated to substitute Nb in SBN50 39 and create a charge-compensating defect of oxygen vacancy.…”

Effect of silica sintering additive on the sintering behavior and dielectric properties of strontium barium niobate ceramics

“…For instance, the relative density of SBN synthesized by partial coprecipitation method 12 could reach 92.25% by sintered at 1300 • C for more than 24 h. With high purity starting powders, SBN sample with a high relative density (∼98.7%) could be obtained by reaction sintering in oxygen atmosphere. 11 Although the two ways mentioned above had effectively improved the density, they both increased the complexity of fabrication to some extent. The first one required twice long-time grinding and a long sintering time, while twice precursor calcinations and a controlled atmosphere were essential to the second.…”

“…5,6 However, the high-density SBN ceramics are difficult to obtain because of the abnormal grain growth. 7 Researches have been done to improve the density of SBN in many ways, such as dual-stage sintering, 8 hot pressing, 9 reaction singtering 10 and atmosphere sintering 11 etc. For instance, the relative density of SBN synthesized by partial coprecipitation method 12 could reach 92.25% by sintered at 1300 • C for more than 24 h. With high purity starting powders, SBN sample with a high relative density (∼98.7%) could be obtained by reaction sintering in oxygen atmosphere.…”