Electronic and structural properties of ZrO2-SiO2 mesoporous films probed by XANES

LEANDRO R. ANDRINI; PAULA C. ANGELOMÉ; GALO J. A. A. SOLER-ILLIA; FELIX G. REQUEJO

Campinas, SP, Brasil

Conferencia; 6º International Conference on Synchrotron Radiation in Materials Science; 2008

Laboratorio Nacional de Luz Sincrotron, LNLS

The mesoporous oxide films supported on different substrates present varied spectra of applications. It is important to understand electronic and structural characteristics for tailoring their mechanical, physicochemical, magnetic and related properties. Taking advantage of X-ray absorption based techniques to probe structural and electronic characteristics in a local range order; we studied the local environment of Si and Zr by XANES in a set of six samples ZrO2-SiO2 on different substrates and relative ZrO2 concentrations. Samples were synthesized to have a homogeneous oxide film with novel and unique properties for diverse applications. Zr L3 XANES split quantitatively probes the Zr environment by effects of crystal field on Zr ions in samples with lower ZrO2 concentrations. Zirconium environment results higher distorted (with closer oxygen neighbours) for lower Zr concentrations (£ 7 w/w %). Si K XANES results revealed that there is not formation of zircon phase. In addition, the Si K XANES experiments probe the electronic nature of Si by the white line intensity: the higher the SiO2 concentration the lower density of electronic holes for Si in SiO2.