Preparation and characterization of negative thermal expansion Sc 2W 3O 12/Cu core–shell composite

Abstract

A composite of Sc 2W 3O 12/Cu where Sc 2W 3O 12, the core, is coated by the Cu shell was synthesized using simple electroless plating method. As-prepared Sc 2W 3O 12/Cu composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and thermomechanical analyzer (TMA) techniques. The study results show that the Pd–Sn activator was successfully formed on the surface of Sc 2W 3O 12 after the sensitization and activation. In the electroless plating process, Cu nanocrystals formed firstly, and then grew together to form a continuous coating. Sc 2W 3O 12/Cu core–shell composites exhibit a negative linear coefficient of thermal expansion CTE = −4.47 × 10 −6 °C −1 from room temperature to 200 °C.