Ion beam induced modifications in electron beam evaporated aluminum oxide thin films

Al2O3 thin films find wide applications in optoelectronics, sensors, tribology etc. In the present work, Al2O3 films prepared by electron beam evaporation technique are irradiated with 100 MeV swift Si7+ ions for the fluence in the range 1 × 1012 to 1 × 1013 ions cm−2 and the structural properties are studied by glancing angle X-ray diffraction. It shows a single diffraction peak at 38.2° which indicates the γ-phase of Al2O3. Further, it is observed that as the fluence increases up to 1 × 1013 ions cm−2 the diffraction peak intensity decreases indicating amorphization. Surface morphology studies by atomic force microscopy show mean surface roughness of 34.73 nm and it decreases with increase in ion fluence. A strong photoluminescence (PL) emission with peak at 442 nm along with shoulder at 420 nm is observed when the samples are excited with 326 nm light. The PL emission is found to increase with increase in ion fluence and the results are discussed in detail

AFM and photoluminescence studies of swift heavy ion induced nanostructured aluminum oxide thin films

E-beam evaporated aluminum oxide films were irradiated with 120 MeV swift Au9+ ions in order to induced nanostructure formation. Atomic force microscope (AFM) results showed the formation of nanostructures for films irradiated with a fluence of 1 à 1013 ions cm-2. The particle size estimated by section analysis of the irradiated film was in the range 25-30 nm. Glancing angle X-ray diffraction (GAXRD) revealed the amorphous nature of the films. Two strong Photoluminescence (PL) emission bands with peaks at â¼430 nm and â¼645 nm besides a shoulder at â¼540 nm were observed in all irradiated samples. The PL intensity is found to increase with increase of ion fluence. © 2008 Elsevier B.V. All rights reserved

Reductive annealing for generating Se doped 20 wt Ru C cathode catalysts for oxygen reduction reaction

Reductive annealing was chosen as a method for the syntheses of Se modified Ru C catalysts. Initial preparation of a 20 wt Ru C was performed by impregnating RuCl3.2H2O on Vulcan XC72 with subsequent conditioning using H2 at 250 C for 4 h. Surface treatment of Ru C by SeO2 followed by reductive annealing produced Se modified Ru C catalysts having Ru Se 1 0.15 and 1 1 a o. Physical characterization was performed using HRTEM while electrochemical characterization was performed using RDE measurements. From the results it is concluded that presence of Se on Ru has the positive effect in the ORR of RuSe C catalyst systems with an optimal loading of Se close to Ru Se ratio of 1 0.15 a