Effect of the cation on the phase composition of nanocrystalline dioxides of the titanium family synthesized by hydrothermal treatment of amorphous hydroxide gels

The phase composition of TiO 2 , ZrO 2 , and HfO 2 nanopowders manufactured by hydrothermal treatment of amorphous hydroxide gels at T = 523 K and the saturated water vapor pressure (for T from 10 min to 24 h) or at high pressures of 3.0 or 4.0 GPa (T = 523 K, T = 30 min) is considered in relation to the physicochemical properties of the powders. The samples synthesized are characterized using X-ray powder diffraction, X-ray line broadening analysis (XLB), thermogravimetry, and electron microscopy (SEM and TEM). The BET specific surface areas are determined using nitrogen capillary adsorption. The nature of the cation is shown to affect the phase composition of the nanosized dioxides of the titanium family.