A TRANSMISSION ELECTRON-MICROSCOPY DIFFRACTION AND SIMULATION METHOD FOR EARLY-STAGE STUDIES OF THE EVOLUTION OF GEL-DERIVED ZIRCONIA PRECURSORS

A technique, utilizing transmission electron microscopy, is described that enables the modeling and diffraction simulation of structural dev elopment during the processing of gel-derived products. This technique relies on the determination of the position and relative intensity of diffuse electron diffraction rings from small domains. X-ray diffract ion cannot provide a basis for this analysis. A qualitative microcryst al modeling of the structural changes accompanying the in situ transfo rmation of a zirconia-precursor gel to crystalline ZrO2 is described. A quantitative analysis is possible only after correction for the inel astic diffraction effect and a calibration of the nonlinear response o f the photographic film.