Thermal barrier materials of Yb2O3-ZrO2 system synthesized by laser excitation

Abstract

A low-cost and minimal-processing-step method is demonstrated to synthesize Yb _2 O _3 -ZrO _2 system by laser excitation catalyzed solid-state reaction. With 980 nm CW laser irradiating, near-resonant excitation of Yb ^3+ ions can obviously enhance solid state reaction. As the molar content of Yb _2 O _3 rises from 12.5% to 50%, the lattice parameter of Yb _2 O _3 -ZrO _2 ceramic increases distinctly. Among them, high crystal quality of Yb _2 Zr _2 O _7 and Yb _0.2 Zr _0.8 O _1.9 are synthesized at the laser power of 400 W for 10 s. Two obvious Raman peaks of Yb _2 Zr _2 O _7 represent increased Raman activity. X-ray photoelectron spectroscopy (XPS) and Impedance spectroscopy demonstrate the huge amount of the oxygen vacancies in Yb _0.2 Zr _0.8 O _1.9 . Yb _2 Zr _2 O _7 shows lowest thermal conductivity among all the ceramics studied, within the range of 0.497–0.730 W mK ^−1 from 25 °C to 1200 °C, which indicates a promising thermal barrier material.

Keywords

• thermal barrier coatings (TBCs)
• laser excitation
• Yb2O3-ZrO2 ceramic
• oxygen vacancy
• thermal conductivity