Mechanical toughening in BaTiO3–Au composite thin films

Ceramic films possess inherently high stiffness; however, their brittleness and limited hardness constrain their use in practical applications. In this study, we demonstrate a strategy to concurrently enhance the mechanical and tribological performance of BaTiO3 (BTO) films by incorporating Au nanostructures at controlled molar ratios (BTO:Au = 5:1, 5:3, 5:5 refer to B5A1, B5A3, B5A5). Nanoindentation tests reveal substantial increases in nanohardness and toughness for the B5A1 and B5A3 films. Complementary tribological testing shows notable reductions in both friction coefficient and wear rate, with the B5A1 film exhibiting the most pronounced improvement, which is attributed to the favorable dispersion state of the Au phase. This work highlights an effective pathway for engineering hard yet damage-tolerant ceramic films through metal incorporation and microstructural tailoring.