Films by slurry coating of nanometric YSZ (8mol% Y2O3) powders synthesized by low-temperature hydrothermal treatment

Abstract: Nanocrystalline powders of yttria (8mol.%)-stabilized zirconia have been hydrothermally synthesized from mechanical mixture of ZrO2 xerogel and crystalline Y2O3 by conventional or microwave route, respectively. The treatments have been performed at 110 and/or 150°C for 2h up to 72h, and in the presence of diluted (0.2M) or concentrated solution (2.0M) of (KOH+K2CO3) mineralizer. To reduce the degree of agglomeration, the freshly synthesized powders has been treated under stirring with aqueous solution of poly(vinyl alcohol) (PVA 10wt.%) for 15h at pH 6.8, whereas to favour the formation of coating suspensions, the polymer absorbed powders and poly(ethylene glycol) (PEG) have been added to ethanol/water solution and stirred under ultrasonic agitation. With the different suspensions, various films have been deposited on glass substrates through withdrawal-coating. After drying at 60°C and firing at 600°C, the texture of the different films has been examined and compared with analogous films deposited by the sol–gel method. The effects of both the type of hydrothermal treatment, the concentration of the mineralizer, and the withdrawal-coating speed on the texture of the films are discussed. [Copyright &y& Elsevier]