Raman Spectroscopic Studies on the Formation Mechanism of Hydrous‐Zirconia Fine Particles

The Raman spectra of hydrous‐zirconia fine particles produced by the hydrolysis of various ZrOCl 2 solutions were investigated. The Raman spectra of hydrous zirconia synthesized at HCl concentrations below 1 mol/L were similar to those of monoclinic, crystalline ZrO 2 ; those of hydrous zirconia synthesized at HCl concentrations greater than 1 mol/L showed a crystal structure change. The line width of the Raman bands increased with increasing H + ion concentration. Analyzing the relationship between Raman band width and particle size revealed that the primary particle size of hydrous zirconia was controlled by the H + and Cl − ions, because these ions interfered with the polymerization in a hydrolysis reaction. Based on the experimental results, the formation mechanism for primary particles of hydrous zirconia was determined.