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采用固相烧结法,以Yb2O3、MoO3、Fe3O4为原料制备了Fe2-x Ybx Mo3O12(x=0,0.2,0.4,0.6,0.8,1,1.2,1.4,1.6,1.8,2)系列固溶体,并通过X射线衍射图样、Raman光谱、热分析以及膨胀系数测试对其结构、相变、吸水性及热膨胀性能进行了研究。结果表明Fe2-x Ybx Mo3O12当x≤0.4时是单斜相,当x≥0.6时是正交相,随着x值的增加Fe2-x Ybx Mo3O12材料的相变温度逐渐降低。Fe2-x Ybx Mo3O12含有的水分子可以分为两类,一类吸附在晶体表面对晶格振动没有影响,第二类进入晶体内部对晶格振动产生较大影响,导致负膨胀性质的消失,只有完全失去水分子后才表现负热膨胀性能。
Fe2-x Ybx Mo3O12 (x = 0,0.2,0.4,0.6,0.8,1,1.2,1.4,1.6,1.8,2) series of solid solutions were prepared by solid-state sintering from Yb2O3, MoO3 and Fe3O4 The structure, phase transition, water absorption and thermal expansion were studied by X-ray diffraction pattern, Raman spectroscopy, thermal analysis and coefficient of thermal expansion. The results show that when x≤0.4, Fe2-x Ybx Mo3O12 is a monoclinic phase, and when x≥0.6 is a quadrature phase, the phase transition temperature of Fe2-x Ybx Mo3O12 material gradually decreases with increasing x value. Fe2-x Ybx Mo3O12 contains water molecules can be divided into two categories, one type of adsorption on the crystal surface has no effect on lattice vibration, the second type into the crystal lattice vibration has a greater impact, leading to the disappearance of negative expansion, Negative thermal expansion will only occur if water molecules are completely lost.