An X-Ray Investigation of Some Aqueous Zirconium(IV) Halide, a Hafnium(IV) Chloride, and Some Zirconium(IV) Perchlorate Solutions.

Growth and Structure of Zirconium Hydrous Polymers in Aqueous Solutions

“…If the scattering intensity decreases with associated power law over a wide range of q (at least a decade), the power-law slope provides information about the dimension, D f , of the particle as described in Eq. [2]. However, the scattering data in Fig.…”

“…The equation for I(0) in a linear condensation ZrO 2 crystallites (23). TEM results on precipitated m-ZrO 2 powder indicate that the particles are porous and cubic (21), polymerization can be expressed as…”

Hydrometallurgical Processing Routes in the Synthesis of Advanced Materials

“…However the metastable tetragonal or cubic forms, with eight-fold coordination, generally appear after aqueous processing at temperatures below 200°C or so [22,23], although monoclinic zirconia appears under acidic (pH < I), hydrothermal conditions [24]. In acidic, aqueous solutions, Zr(1V) exists predominantly as [Zr,(OH),(H,0)161a+, a square planar complex in which the four zirconium atoms are linked by pairs or hydroxo bridges, with the oxygen atoms of four water molecules completing the distorted dodecahedral, eight-fold coordination of each zirconium atom [25]. The formation of tetragonal or cubic forms probably reflects the kinetic barrier associated with rearranging the coordination of zirconium during hydrolysis.…”

Dynamic studies of zirconia crystallization

“…The tetramer occurs in the solid ZrOCi2-8H20 structure [15]. This tetramer unit has been found to be very stable, and subsequent work [16][17][18] has shown that it remains intact as a complex ion in solution during hydrolysis of zirconium chloride. Mak [17] indicates that the Zr atoms are connected by hydroxo-bridges whereas the terminal oxygens belong to water molecules of hydration (Fig.…”

“…It is instructive to review the question of the structural unit. While there are no hard data concerning the hydroxide, structural studies on the oxychloride [15,16,18], crystalline basic sulphates [21,22] and all three phases of the oxide [23-253 reveal striking similarities. In particular, the tetramer in the oxychloride can be seen as being closely related to the fluorite structure of the cubic phase, with the tetragonal and monoclinic forms representing the effects of distortions [26].…”