Near‐Infrared Trapping by Surface Plasmons in Randomized Platinum–Ceramic Metamaterial for Thermal Barrier Coatings
Zesheng Yang, Muzhang Huang, Ronggui Yang, Jingbo Sun, Xuefei Zhang, Wei Pan, Chunlei Wan
Abstract
Abstract As the operation temperature of next generation gas turbine is targeted to be 1800 °C toward a higher efficiency and lower carbon emission, the near‐infrared (NIR) thermal radiation becomes a major concern for the durability of the metallic turbine blades. Although thermal barrier coatings (TBCs) are applied to provide thermal insulations, they are translucent to the NIR radiation. It is a major challenge for TBCs to achieve optically thick with limited physical thickness (usually < 1 mm) for effectively shielding the NIR radiation damage. Here, an NIR metamaterial is reported, where a Gd 2 Zr 2 O 7 ceramic matrix is randomly dispersed with microscale Pt (0.53 vol%) nanoparticles with a size of 100–500 nm. Attenuated by the Gd 2 Zr 2 O 7 matrix, a broadband NIR extinction is achieved through the red‐shifted plasmon resonance frequencies and higher‐order multipole resonances of the Pt nanoparticles. A very high absorption coefficient of ≈3 × 10 4 m −1 , approaching the Rosseland diffusion limit for a typical coating thickness, minimizes the radiative thermal conductivity to ≈10 −2 W m −1 K −1 and successfully shields the radiative heat transfer. This work suggests that constructing a conductor/ceramic metamaterial with tunable plasmonics could be a strategy to shield NIR thermal radiation for high temperature applications.