Phase transition and negative thermal expansion properties of Sc2−xCrxMo3O12

Abstract

The crystal structure, phase transition and thermal expansion behaviors of solid solutions Sc2−xCrxMo3O12 (0≤x≤2) were investigated using X-ray diffraction (XRD) and differential scanning calorimetry (DSC). At room temperature, samples with x≤0.7 and x≥0.8 crystallize in orthorhombic and monoclinic structures, respectively. DSC result indicates that the phase transition of Sc0.5Cr1.5Mo3O12 from monoclinic to orthorhombic structure occurs at 203.66°C. The linear thermal expansion coefficient of orthorhombic phases varies from −2.334×10−6°C−1 to 0.993×10−6°C−1 when x increases from 0.0 to 1.5. The near-zero linear thermal expansion coefficients of −0.512×10−6°C−1 and −0.466×10−6°C−1 are observed for compounds with x=0.5 and 0.7, respectively.