$\alpha - $Fe$_{2}$O$_{3}$ films grown by the spin-on sol-gel deposition method

Abstract

$\alpha - $Fe$_{2}$O$_{3}$ polycrystalline films with grains larger than 31 nm were grown by the spin-on sol-gel deposition method. The particular sol used was prepared starting from two distinct precursor reagents. Both precursors leaded to similar films. Order within the films was altered by adding tin to the samples. Transmittance measurements confirmed that the hematite phase is obtained by annealing the samples above 400~$^{\circ}$C and yielded an optical gap of about 2.2 eV, but additional transitions at 2.7 eV were also observed. From RBS measurements it was found that tin inclusion decreases iron content as expected, but also increases oxygen concentration within the films. This last observation was associated to the disorder rise when introducing tin atoms.