Structural and electrical properties of sintered Fe 2 O 3 /TiO 2 nanopowder mixtures

AbstractStarting nanopowders of TiO 2 (anatase 99.7%) and α-Fe 2 O 3 (hematite) were mixed in the weight ratios 60:40 and 40:60. Green samples weresintered in the temperature range 750–1250 1C in air. Structural, morphological and electrical studies were carried out using XRD, SEM and EDSanalysis, Hall measurements and electrical conductivity measurements. The aim was analyzing the influence of the starting nanopowder structureon the resulting sample composition, density, grain size and electrical resistivity in view of tailoring properties for developing differentapplications such as anodes for photoelectrochemical cells, photocatalysts and gas sensors. Compared to pure anatase samples, the presence ofhematite lowered the temperature of completion of the anatase to rutile phase transformation to 850 1C. Formation of pseudobrookite was alsonoted at this temperature. Higher sintering temperatures lead to increased sample density, changes in grain size (grain growth and inhomogenousmicrostructure) and decreased electric resistivity.& 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.