Preparation and characterization of negative thermal expansion Sc2W3O12/Cu core–shell composite

A composite of Sc2W3O12/Cu where Sc2W3O12, the core, is coated by the Cu shell was synthesized using simple electroless plating method. As-prepared Sc2W3O12/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 Sc2W3O12 after the sensitization and activation. In the electroless plating process, Cu nanocrystals formed firstly, and then grew together to form a continuous coating. Sc2W3O12/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.