Crystal Textures of Hydrous ZrO₂ Particles

The particles of hydrous ZrO2, which were prepared by hydrolysis of ZrOCl2 solution (0.1mol/l) at 100°C for 140h, were observed under electron microscope, by means of bright-field, dark-field and electron diffraction techniques. The particles are square-like in shape and about 1000Å in size. The particles are made up of a great number of rod-shaped crystals about 100Å long and 30-50Å wide. The long axes of the crystals coincide with the crystallographic direction of ‹101› or ‹101›. The crystals are oriented in such a way that their long axes coincide in direction with the diagonals of the square-like particles.The electron diffraction patterns of each particles were composed of (hOl) reflection spots and strikingly resembled to that of the (100) twinned crystals. But the radial streak of each spots showed the slight variation of each rod-shaped crystals in orientation.Lattice images of (100) and dark-field images of (200) and (002) were observed in the whole area of the square-like particles.