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.

The Influence of Reactive PS-PVD Process Parameters on the Microstructure and Thermal Properties of Yb2Zr2O7 Thermal Barrier Coating

“…When the power current was increased up to 2000 or 2200, the thermal conductivity decreased. The observed trends in thermal conductivity changes with temperature are almost opposite the thermal conductivity of the Yb 2 Zr 2 O 7 coating synthetized using the laser excitation method [24]. On the other hand, the Reactive PS-PVD forms an YZO coating characterized by other structure (hybrid or quasi-columnar), which has different thermal properties.…”

“…For comparison, the prepared powder mixture was calcinated at 1500 • C. Powders were mixed with polyvinyl alcohol additive (about 2 wt.%) and spray dried. For synthesis of ytterbium zirconate during reactive PS-PVD process, the methodology of coating formation proposed by He [24] was used. The ytterbium zirconate coating was formed in the reactive PS-PVD process during the following reaction:…”

“…The hot corrosion in the presence of V 2 O 5 was investigated by Li [23]. An investigation conducted by He et al [24] showed that Yb 2 Zr 2 O 7 might by synthetized from pure ZrO 2 and Yb 2 O 3 powders using the laser excitation process. The obtained results showed the presence of pure oxides in the obtained coating.…”

Low-temperature properties of magnetically frustrated rare-earth zirconates A 2Zr2O7

“…In addition to particular magnetic properties connected also with geometrical frustration, defect-fluorite members have great application potential. The specifics of their defects, bonding character, and crystal structure allow their use in solid oxide fuel cells [16,17], thermal barrier coatings [18,19], or nuclear waste storage [20,21]. Several A 2 B 2 O 7 members were found to crystallise in lower-symmetry structures: monoclinic [22], orthorhombic [23], and very recently Lu 2 Zr 2 O 7 was reported to adopt a rhombohedral structure (space group R-3) [24].…”