Simultaneously Enhancing the Luminescence and Thermophysical Properties of the YSZ Thermal Barrier Coating via Eu‐Gd‐Dy Combined Doping

Abstract The temperature measurement technology of thermal barrier coatings is very important and urgent. Thermal phosphorescence temperature measurement technology is a potential solution. In this study, an Eu‐Gd‐Dy combined doped yttria‐stabilized zirconia (YSZ) thermal barrier coating material is synthesized via a high‐temperature solid‐state method. The phase composition, luminescent properties, energy transfer behavior, thermal conductivity, and thermal expansion coefficient of the coating material are systematically analyzed. The results showed that the luminescence intensity of Eu 3+ at 590 nm ( 5 D 0 → 7 F 1 ) and 606 nm ( 5 D 0 → 7 F 2 ) increased by ≈1.5 times at both room temperature and 500 °C upon doping with Gd 3+ and Dy 3+ . This enhancement is attributed to efficient energy transfer from Gd 3+ → Eu 3+ and Dy 3+ → Eu 3+ . Furthermore, the doping elements effectively reduced the thermal conductivity of the YSZ thermal barrier coating material. The lowest thermal conductivity reaching 1.998 W m −1 °C −1 at 1200 °C for the YSZ: Eu, Gd, Dy sample, reducing 17.26% compared with the YSZ sample. Specifically, the Eu‐Gd‐Dy combined doping significantly improved the thermal insulation performance of YSZ, while maintaining a comparable thermal expansion coefficient. This study suggests that suitably combined doped YSZ has significant potential for temperature measurement technology of thermal barrier coatings.