Abstract In this work, Yb2Si2O7 powder was synthesized from Yb2O3 and SiO2 powders and applied to aluminum substrates by atmospheric plasma spraying. Phase composition and microstructure were examined and density, porosity, and hardness were assessed. Thermal stability was evaluated by thermogravimetry and differential thermal analysis and thermal conductivity was measured. The as-sprayed coating was mainly composed of crystalline Yb2Si2O7 with a small amount of Yb2SiO5 and amorphous Yb2Si2O7. It had a dense structure containing pores, microcracks, and other types of defects. TG-DTA tests showed that there was almost no mass change from room temperature to 1200 °C, although a sharp exothermic peak appeared at 1038 °C, indicating that the amorphous phase had crystallized. The thermal conductivity of the coating decreased with increasing temperature, reaching a minimum of 0.68 W/(m·K) at 600 °C, followed by an increase at higher temperatures.