Preparation of Oxide Powders by Hydrothermal Salt Solution Pressure-relief

α-Al2O3 powder, AlO(OH) fibers and complex oxides made up of ZrO2 and AIO(OH) were prepared by a new hydrothermal method-hydrothermal salt solution pressure-relief. α-Al2O3 powders were prepared at 300℃ by using 1mol/L Al(NO3)3 solution as precursor, 0.2mol/L Fe(NO3)3 as additive; AlO(OH) fiber with the ratio of length with diameter 13:1 were prepared at 350℃ by using 1mol/LAl(NO3)3 as precursor, 1 mol/L KBr as additive; complex oxides made up of ZrO2 and AlO(OH) were prepared at 240℃ by using 0.75mol/L AlC13 and 0.25mol/L ZrOCl2 mixed solutions as precursor.