Grazing-incidence X-ray diffraction supplemented with atomic force microscopy and secondary ion mass spectroscopy were applied to the characterization of films deposited by laser ablation on cold substrates from YBaCuO targets and subsequently irradiated with additional laser pulses of lower energy density. Evolution of X-ray diffraction pattern was observed as a function of irradiation dose. For the as-deposited films the pattern was typical of the amorphized solids. For the films irradiated with doses higher than the threshold, the pattern was enriched with the diffraction peaks, whose general features, like peak positions, widths and relative intensities were almost independent of the dose. The size of the crystallites was deduced from the peak widths to be not smaller than 12-16 nm. Comparison of the pattern with patterns of known phases indicates that, apart of the amorphous component, a structure with an admixture of some new metastable or high temperature phase(s) is formed during the process of pulsed laser annealing. The atomic force microscopy observations revealed that the surface roughness shows a pronounced minimum at low irradiation doses. The secondary ion mass spectroscopy investigation confirms that the strongest chemical changes (increase in concentration of yttrium and copper) due to irradiation with higher doses are observed in the near-surface film material.
This work is devoted to the production of microparticles via pulsed laser ablation from a solid cobalt target immersed in three different solutions of distilled water as well as in ethanol and in acetone, to study the effect of liquid media on the physical properties and structure of particles. The samples were characterized using XRD, SEM and particle size analysis. More than simply Co particles have resulted in each three liquid media, CoO particles were produced only in acetone, whereas Co₃O₄ particles were predominantly produced in water and ethanol.
The propagation of laser beam in the plasma has been investigated for two cases, first with imposing the restriction of paraxial approximation on the beam profile, and second, relaxing the restriction on the profile up to a certain extent. The beam width parameter of the propagating laser beam has been compared for both the cases. Since the off-paraxial part of the beam affects background densities, consequently it will also influence the 2nd harmonic generation. Therefore, comparison of results has been done on the generated second harmonic, in the light of these two cases. A notable change is found in the magnitude of second harmonic yield in modified-paraxial case as compared to the paraxial case.
In this work, the pulsed laser deposition (PLD) technique was used to grow AlMg thin films from a β-Mg_{2}Al_{3} target with nominal composition: 39.09 at.% Mg and 60.91 at.% Al. The paper presents the study of β-Mg_{2}Al_{3} thin films deposited using the pulsed laser deposition technique. AlMg thin films were prepared on Si (400) substrates and deposited by means of using a QS-Nd:YAG laser (λ = 266, 355 nm). Samples were prepared with laser fluence (1.1 J/cm^{2} and 1.6 J/cm^{2}) and at two different substrate (Si) temperatures (25°C and 200°C). The target possessed columnar structure and changes in chemical composition took place as a result of the influence of the laser irradiation. Investigations focused on structure and chemical composition showed that the films generally had nanocrystalline structure and that the quantity of Al and Mg varied in the films.
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