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Pulsed Laser Ablation (pulsed + laser_ablation)
Selected AbstractsSurfactant-Assisted Preparation of Novel Layered Silver Bromide-Based Inorganic/Organic Nanosheets by Pulsed Laser Ablation in Aqueous Media,ADVANCED FUNCTIONAL MATERIALS, Issue 17 2007C. He Abstract A novel layered AgBr-based inorganic/organic nanocomposite was prepared by pulsed laser ablation (PLA) of Ag in aqueous media in the presence of cetyltrimethylammonium bromide (CTAB), and the formation mechanism of two-dimensional nanosheet was discussed. TEM observations indicate that the obtained AgBr-based inorganic/organic nanocomposite possesses a well-defined two-dimensional shape and that the size of the nanosheet can be changed with the surfactant concentration in the solution. X-ray diffraction (XRD) pattern was composed of a series of peaks that could be indexed to (00l) reflections of a layered structure, and the basal spacing of 20.0,Å indicated that the surfactant was included between the AgBr interlayers in an interdigitated bilayer arrangement. In contrast, a layered inorganic/organic nanocomposite cannot be formed at a CTAB concentration lower than the critical micelle concentration (CMC). Based on our detailed investigation, we proposed the nanocomposite formation process, that is, that negatively charged inorganic AgBr was produced by a strong reaction between the ablated Ag species and the bromide ions, which are concurrently assembling with cationic surfactant molecules controlled by the charge-matching mechanism. [source] X-ray diffraction and Raman study of nanogranular BaTiO3,CoFe2O4 thin films deposited by laser ablation on Si/Pt substratesPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 6 2007J. Barbosa Abstract Nanocomposite thin films composed by (BaTiO3)1,x,(CoFe2O4)x with different cobalt ferrite concentrations (x) have been deposited by pulsed laser ablation on platinum covered Si(001) substrates. The films structure was studied by X-ray diffraction and Raman spectroscopy. It was found that the CoFe2O4 phase unit cell was compressed along the growth direction of the films, and it relaxed with increasing x. The opposite behavior was observed in the BaTiO3 phase where the lattice parameters obtained from the X-ray measurements presented a progressive distortion of its unit cell with increasing x. The presence of the strain in the films induced a blueshift of the Raman peaks of CoFe2O4 that decreased with increasing CoFe2O4 concentration. Cation disorder in the cobalt ferrite was observed for lower x, where the nanograins are more isolated and subjected to more strain, which was progressively decreased for higher CoFe2O4 content in the films. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Self-organized regular surface patterning by pulsed laser ablationPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 3 2009Juergen Reif Abstract The impact of intense ultra short laser pulses on solid surface - as in laser ablation - results in a transient perturbation of the material to a state far from equilibrium. Due to ultrafast relaxation of the transient disorder in a few picoseconds, self-organized surface patterns occur, with a typical feature size at the order of 100 nm or less, similar as observed in ion sputtering and explained by non-linear dynamics models. The feature size of these structures is determined by the deposited energy dose, their shape and orientation crucially depends on the state of polarization of the incident light. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | ||||||||||