ФАЗОВЫЕ ПРЕВРАЩЕНИЯ ПРИ КРИСТАЛЛИЗАЦИИ ТВЕРДОГО РАСТВОРА СТРОНЦИЙ-ЗАМЕЩЕННОГО ДВОЙНОГО ПЕРОВСКИТА
ФАЗОВЫЕ ПРЕВРАЩЕНИЯ ПРИ КРИСТАЛЛИЗАЦИИ ТВЕРДОГО РАСТВОРА СТРОНЦИЙ-ЗАМЕЩЕННОГО ДВОЙНОГО ПЕРОВСКИТА
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ПРЕВРАЩЕНИЯ ПРИ КРИСТАЛЛИЗАЦИИ ТВЕРДОГО РАСТВОРА СТРОНЦИ Й-ЗАМЕЩЕННОГО ДВОЙНОГО ПЕ ОВСКИТА
DOI：
10.35596/1729-7648-2019-126-8-73-80
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
А. В. Петров
中科院分区：
文献类型：
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作者：
А. Л. Гурский;Н. А. Каланда;М. В. Ярмолич;И. А. Бобриков;С. В. Сумников;А. В. Петров
研究了固相法从SrCO 3 + BaCO 3 + 0，5 Fe 2 O3 + MoO 3简单氧化物中晶化SrBaFeMoO 6- δ过程中相含量变化的动力学。在300-1200° C的温度范围内，已经检测到许多内温效应。其中，第一个（最大值约为552° C）和第三个（最大值约为743° C）伴随着样品质量的显著减少。在946-1200° C的温度范围内，样品的质量变化几乎不明显，但热效应仍然存在，样品仍然不是单相的。这表明了钡锶铁氧体固溶体形成过程中固相反应流动的困难性。在分析SrCO 3 + BaCO 3 + 0，5 Fe 2 O3 + MoO 3初始试剂组成的相组成变化过程中，发现随着温度的升高，络合物BaMoO 4，SrFeO 3几乎同时出现，随后出现SrBaFeMoO 6- δ。因此，化合物BaMoO 4 <$SrFeO3是形成钡锶铁氧体固溶体的结构。当温度进一步升高到770° C时，发现有新化合物α-FeO 3生成，而SrFeO 3消失。在这种情况下，双钙钛矿的量比钡钙钛矿的量增加得更快。SrBaFeMoO 6- δ双钙钛矿固溶体晶化过程中的主要伴生物为BaMoO 4和SrFeO 3。已经确定，在相互作用的初始阶段，所得到的钡-锶铁氧体的固溶体富含铁，并且其组成在反应期间在钼含量增加的方向上变化，如在其他前体组合的情况下。
The kinetics of phase contents modification in the process of SrBaFeMoO 6– δ crystallization from a stoichiometric mixture of SrCO 3 + BaCO 3 + 0,5Fe 2 O 3 + MoO 3 simple oxides using the solid phase method has been investigated. In the temperature region of 300–1200°С, a number of endotermic effects have been detected. Herewith, the first one (with maximum around 552°С) and the third one (with maximum around 743°С) are accompanying by the significant decrease of the mass of specimen. In the temperature range of 946–1200°С, the mass change of specimen is practically not observable, while the thermal effect is still present, and the specimen remains not single-phase one. This indicates the difficulty of the flow of solid phase reactions with the formation of solid solution of barium-strontium ferromolybdate. During analysis of the change of the phase composition consisting of a mixture of initial reagents of stoichiometric relation SrCO 3 + BaCO 3 + 0,5Fe 2 O 3 + MoO 3 , it has been observed that with increasing temperature, complex compounds BaMoO 4 , SrFeO 3 appear almost simultaneously, then SrBaFeMoO 6– δ appears consequently. Thus, the compounds BaMoO 4 и SrFeO 3 , are structure forming for the solid solution of barium-strontium ferromolybdate. With further temperature increase up to 770°С the formation of new compound ВаFeO 3 with disappearing SrFeO 3 was detected. In this case, the amount of double perovskite increases faster than that of barium molybdate. The main accompanying compounds at the crystallization of the SrBaFeMoO 6– δ double perovskite solid solution are BaMoO 4 and SrFeO 3 . It was established that at the initial stage of the interaction, the resulting solid solution of barium-strontium ferromolybdate is enriched with iron and its composition changes during the reaction in the direction of an increase of the molybdenum content, as in the case of other precursor combinations.