Scandium Molybdate Nanofibers with Negative Thermal Expansion for Fabricating Composites with Controllable Coefficients of Thermal Expansion

Single-crystal Sc2Mo3O12 nanofibers, an one-dimen sional negative thermal expansion (NTE) material, have been successfully synthesized by electrospinning. The crystal structure, morphology, and NTE property of Sc2Mo3O12 nanofibers were characterized using typical X-ray diffraction (XRD), scanning electron microscopy (SENt), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDX), and variable-temperature XRD. Results indicate that as deposited Sc2Mo3O12 nanofibers are amorphous and display a smooth surface and uniform diameter. Single-crystal Sc2Mo3O12 nanofibers are fabricated at 500 degrees C for 3 h and grown along the (111) orientation with an orthorhombic structure. The average diameter of single-crystal Sc2Mo3O12 nanofibers is similar to 100 nm. Sc2Mo3O12 nanofibers exhibit anisotropic NTE with an average volumetric coefficient of thermal expansion (CTE) of -6.53 X 10(-6) degrees C-1 from 25 degrees C to 700 degrees C. The average CTEs along the a-, b-, and c-axes are -6.62 x 10(-6), 5.33 X 10(-6), and -5.21 X 10(-6) degrees C-1 respectively.