Phases of variable composition AА'MgZr(PO) (АA' – KNa, KRb, KCs, 0 ≤ ≤ 2) with langbeinite and kosnarite structures can serve as matrices immobilizing radioactive waste. They were synthesized by sol-gel method followed by heat treatment and investigated by X-ray diffraction at different temperatures, IR spectroscopy, scanning electron microscopy and electron probe microanalysis. A Rietveld refinement of the KCsMgZr(PO) structure showed that the framework is formed by octahedra (Mg/Zr)O and tetrahedra PO connected by vertices; potassium and cesium cations are located in cavities. When the temperature changes, phosphates with the langbeinite structure expand uniformly in all directions: α = α = α = (4.2−6.6) ∙ 10 °C, without undergoing polymorphic transitions. Phosphate NaMgZr(PO), which crystallizes in the kosnarite structure type, expands anisotropically: α = −2.6·10, α = 8.2·10, α = 1.0·10 °C. The chemical durability test shows that the leaching rate of Cs ions from the solid solution with langbeinite structure is of the order of 10 g cm d.

中文翻译：

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碱性元素、镁和锆的复合磷酸盐的合成和表征，作为核废料固定的潜在陶瓷

具有硅锰矿和硅钠石结构的可变成分 A−'MgZr(PO)（−A' – KNa、KRb、KCs，0 ≤ ≤ 2）相可用作固定放射性废物的基质。采用溶胶-凝胶法合成并热处理，并通过不同温度下的X射线衍射、红外光谱、扫描电子显微镜和电子探针微分析进行研究。对KCsMgZr(PO)结构的Rietveld精修表明，骨架由八面体(Mg/Zr)O和四面体PO通过顶点连接形成；钾和铯阳离子位于空腔中。当温度变化时，具有朗贝氏体结构的磷酸盐在各个方向上均匀膨胀：α = α = α = (4.2−6.6) ∙ 10 °C，而不发生多晶型转变。磷酸盐NaMgZr(PO)以科钠长石结构类型结晶，各向异性膨胀：α = -2.6·10、α = 8.2·10、α = 1.0·10 °C。化学耐久性测试表明，Cs离子从钙锰矿结构固溶体中的浸出率为10 g·cm·d量级。