Fine particles and thin films of NiO/SiO2 mixed gels, prepared from a bidentate alkoxide, were irradiated by a XeCl excimer laser or by a corona discharge. A part of NiO was initially dissolved in SiO2, and was segregated and crystallized on heating at 10 K min-1 to 800°C in air. Subsequently, amorphous SiO2 crystallized into cristobalite at 900°C. Based on the change in the interplanar spacing of cristobalite, ultraviolet irradiation or discharge promoted the segragation of NiO. Transmission electron micrographs of substrateless gel thin films revealed that corona discharge treatment brought about the formation of uniform NiO particles as small as 5 nm.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry