Specific features in the behavior of amorphous zirconium hydroxide: I. Sol-gel processes in the synthesis of zirconia

Finely crystalline zirconia powder with a crystal size of less than 100 nm is synthesized. It is found that, upon decomposition of zirconium hydroxide, the amorphous phase is formed as an intermediate product. This phase is structurally disordered and involves impurities (OH- and H2O). It is demonstrated that the crystallization of amorphous zirconium hydroxide under different conditions provides a way of preparing low-temperature tetragonal and cubic or monoclinic zirconia modifications.