Neutron and X-ray diffraction studies on pure and magnesia-doped zirconia gels decomposed in vacuo

Abstract

Pure and MgO-doped zirconia gels have been decomposed in vacuo at temperatures up to 800° C in a furnace attachment to the D1B neutron spectrometer at Institute Laue-Langevin (I LL). The recorded neutron line profile data were analysed to obtain a measure of the crystallite size of the product phase and the growth of the crystallites with increasing temperature; phase changes occurring during heating were also monitored. Additionally, the gel powders were decomposedin situ in a high temperature attachment to a Philips diffractometer and X-ray diffraction traces were obtained during progressive heating of the samples and after thermal cycling over a range of temperatures. The peak profiles were analysed to provide both crystallite size and strain values in the decomposed powders. The crystallite size values obtained from the two studies are compared with those obtained from a parallel small angle neutron scattering (SANS) study of the same gels after calcination.