Preparation of Sc<sub>2</sub>Mo<sub>3</sub>O<sub>12</sub> and Characterization of its Negative Thermal Expansion Property

Negative thermal expansion (NTE) material Sc 2 Mo 3 O 12 was prepared by solid-state method. The phase structure, morphology and the thermal stability of the obtained products were examined by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric-differential thermal analysis (TG-DSC), respectively. To study its negative thermal expansion property, two methods were utilized. One is based on the in-situ XRD results and the thermal expansion coefficient (CTE) was calculated by the cell parameters obtained at different temperatures. Another is based on the thermo-mechanical analysis (TMA) and the CTE was calculated by the length of Sc 2 Mo 3 O 12 bar at different temperatures. The differences between these two methods were also discussed.