S B Ogale
Articles written in Bulletin of Materials Science
Volume 11 Issue 2-3 November 1988 pp 88-88
Volume 11 Issue 2-3 November 1988 pp 137-157
The field of laser-induced synthesis, deposition and etching of materials is reviewed with an emphasis on the emerging trends and novel adaptations of the basic laser processing concepts. A number of examples are cited to illustrate the issues involved. These include rapid synthesis of titanium nitride by pulsed laser induced reactive quenching at Ti:liquid NH3 interface, laser deposition of good quality thin films of such materials as hot oxide superconductors, zinc ferrite, iron oxide, stainless steel, etc. and laser etching of superconductor films.
Volume 11 Issue 2-3 November 1988 pp 167-190
Recent results on high-power pulsed-laser-induced transformations at liquid-solid interface are described in the context of synthesis of new metastable phases of materials. Specifically two types of problems are reported: (i) laser-induced synthesis of compound film at liquid solid interface, this process being termed “reactive quenching”, and (ii) laser-induced alloying of layered structure under liquid medium wherein the reactive aspect plays the minimal role. So far the reactive quenching process has been studied for different metals, compounds and thin film sandwiches in various liquid ambients such as H2O, liquid ammonia (NH3), liquid N2 and benzene (C6H6). The identification of the metastable phases and the microstructural transformations therein subsequent to laser processing and thermal annealing have been brought out by employing a range of techniques such as conversion electron Mössbauer spectroscopy (CEMS), X-ray diffraction (XRD), Rutherford backscattering spectrometry (RBS), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), etc. Laser-induced alloying of layered structure in liquid ambient has been investigated in case of Fe/Al and Fe/B systems. The possible mechanism which could be responsible for the observed effects is discussed on the basis of time-resolved reflectivity measurements.
Volume 13 Issue 1-2 March 1990 pp 51-56 First National Seminar On GaAs And III–V Compound Semiconductors
The progress in the area of applications of ion implantation and laser treatment to III–V semiconductors is reviewed. The achievements till todate are discussed alongwith the yet unresolved problems.
Volume 14 Issue 2 April 1991 pp 435-441 International Conference On Superconductivity—I
Ion beam and thermally-induced interface reactions between high
Volume 14 Issue 2 April 1991 pp 443-449 International Conference On Superconductivity—I
Thin films of Y-Ba-Cu-O superconductor have been deposited on different substrates by pulsed excimer laser ablation from a superconducting pellet. The dependence of various process parameters such as substrate temperature, laser energy density, oxygen partial pressure, applied bias field and cooling rates on the quality of the films has been studied.
Volume 14 Issue 5 October 1991 pp 1249-1255
Non-contact processing technique involving the use of CW and pulsed CO2 laser irradiation has been used for reducing the core loss of cold-rolled grain-oriented silicon steel. Laser scribing perpendicular to the rolling direction resulted in a refinement of domain wall spacing which subsequently reduced the loss of silicon steel. It was found that laser irradiation was more effective in a specimen with higher magnetic induction (Hi-B) and the loss was reduced by more than 10% under optimum conditions of the laser irradiation and the scribing speed. Since laser processing is a non-contact technique, it can be easily applied to the production line of the silicon steel.
Volume 15 Issue 4 August 1992 pp 377-384
Superconducting thin films of Y1Ba2Cu3 O7 −
Volume 17 Issue 6 November 1994 pp 829-839
Diamond like carbon films and C-N films were prepared using ion beam assisted deposition technique (IBAD). Tribological properties were studied by subjecting DLC coated films to the accelerated wear tests. These tests indicated a significant improvement in the mechanical surface properties of glass by DLC coating. Better wear features were obtained for thinner DLC coating as compared to the thicker ones. We also studied the optical properties and obtained a band gap of 1·4 eV for these films. An attempt was made to prepare C3N4 films by using IBAD. We observed variation in the nitrogen incorporation in the film with the substrate temperature.
Volume 22 Issue 2 April 1999 pp 95-101 Surfaces
Surface complexes involving silicon, germanium and carbon adatom on predefined adsorption sites of the 2×1 reconstructed Si(001) surface are investigated for their energetics and associated structural relaxations. Tersoff’s semi-empirical potential is used and the relaxations are obtained by employing the Monte Carlo simulated annealing technique. The results for the cases of Si, Ge and carbon adsorptions are compared. It is found that Si and Ge as adatoms on Si(001) 2×1 reconstructed surface behave in a similar fashion but the carbon adatom behaves in a markedly different way. Specifically, the carbon adatom induces a Si-C-Si chain configuration. It is also found that the adsorption sites between two dimer rows are the most favourable ones.
Volume 42 | Issue 6
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