本文对Fe2-xYx(MoO4)3(x ＝0.0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0)系列材料的相变及负膨胀性能进行了研究。通过对Fe2-xYx(MoO4)3系列材料的XRD和拉曼谱的分析发现, 当x≤0.4时Fe2-xYxMo3O12在常温下是单斜结构; 当x≥0.5时变为正交结构, 即提高Y3+的含量可有效地降低Fe2-xYx(MoO4)3从单斜相转变为正交相的相变温度。同时随着Y3+含量的增加, 正交相Fe2-xYx(MoO4)3在释放全部结晶水之后的膨胀系数逐渐减小, 当x＝1.0时为近零膨胀材料; x＜1.0时为膨胀系数较低的材料; x＞1.0时为负膨胀材料。

The phase transition and negative thermal expansion of Fe2-xYxMo3O12 (x＝0.0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6 and 1.8) have been studied. It is found that Fe2-xYxMo3O12 crystallize in a single monoclinic for x≤0. 4and a single orthorhombic structure for x≥0.5 by the analysis of Raman spectroscopy and X-ray diffraction. The monoclinic to orthorhombic phase-transition temperature can be effectively decreased by increasing the content of Y3+. It is shown that the coefficients of thermal expansion (CTE) decrease with increasing the content of Y3+ and orthorhombic Fe2-xYxMo3O12 exhibits negative (x＞1.0), near zero (x＝1.0) and low (x＜1.0) thermal expansion properties after remove of the crystal water.