Publications by authors named "Nikolaos Chazapis"

Recently, the preparation of some hematene and magnetene ultrathin non van der Waals (non-vdW) 2D nanoplatelets was reported starting from hematite and magnetite natural iron ores. The present work reports on the determination and evaluation of the nonlinear optical response and the optical limiting (OL) action of these 2D nanoplatelets dispersed in water under ns laser excitation. The obtained results show that both hematene and magnetene exhibit strong nonlinear absorption and refraction, comparable and even larger than those of other van der Waals (vdW) 2D counterpart materials.

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The present work reports on the synthesis and characterization of iridium (Ir)-based nanohybrids with variable chemical compositions. More specifically, highly stable polyvinylpyrrolidone (PVP) nanohybrids of the PVP-IrO and PVP-Ir/IrO types, as well as non-coated Ir/IrO nanoparticles, are synthesized using different synthetic protocols and characterized in terms of their chemical composition and morphology via X-ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy (STEM), respectively. Furthermore, their nonlinear optical (NLO) response and optical limiting (OL) efficiency are studied by means of the Z-scan technique, employing 4 ns laser pulses at 532 and 1064 nm.

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In the present work, some non-van der Waals (non-vdW) 2D materials, namely, hematene and magnetene nanoplatelets, were synthesized starting from hematite and magnetite ores, respectively, using a green synthesis method, and they were dispersed in water. Then, their ultrafast nonlinear optical (NLO) response was studied under 50 fs, 400 nm laser excitation. Both non-vdW 2D materials revealed strong saturable absorption with NLO absorption coefficient β, saturable intensity, and modulation depth of about -33.

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The third-order nonlinear optical (NLO) properties of a series of platinum diimine-dithiolate complexes [Pt(N^N)(S^S)] were investigated by means of -scan measurements, revealing second hyperpolarizability values up to 10 esu, saturable absorption properties, and nonlinear refractive behaviour, which were rationalized also by means of DFT calculations.

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