Synthesis of Nanomaterials by Laser Ablation

Saitow Synthesis of Nanostructures via Long-Pulse-Duration Laser Ablation in Liquid Media, X.

Synthesis of Nanomaterials by Laser Ablation W

AB - Copper nanoparticles (Cu-NPs) were prepared in virgin coconut oil (VCO) using a laser ablation technique. A copper plate immersed in VCO was irradiated by an Nd:YAG laser at wave lengths of 532 nm for 5, 10, 20, and 30 min. By increasing the ablation time from 5 to 30 min, the particle size inside the nanofluid decreased from 11 to 4 nm and the concentration, refractive index, and the volume fraction of copper nanofluid increased. The Cu-NPs were capped with oxygen from hydroxyl groups of the VCO, as verified by Fourier transform infrared spectroscopy. The refractive indices, obtained by analysis of the surface plasmon resonance signals increased from 1.44371 + 0.0034i to 1.44387 + 0.0142i, and special self-phase modulation due to nonlinearity effect was investigated.

Sun Pulsed Laser Ablation Synthesis and Modification of Composite Nanoparticles in Liquids, N.

Synthesis of Ni Nanoparticles by Femtosecond Laser Ablation in ..

Laser ablation of solid targets in liquid environment allows the generation of nanoparticles (NPs) with several useful properties such as high purity, easily functionalizable surface, metastable composition, or complex structure, including doped nanocrystals, core–shells, hollow microspheres, nanotruffles, or nanocrescents. However, the mechanisms of NPs formation is still not well understood, and challenges remain in size control and productivity. Here, we investigate how the asymmetry intrinsic of laser-matter interaction can influence the structure and yield of gold NPs produced with nanosecond pulses. In particular, we confined the geometry of the laser ablation configuration in three ways: by reducing the thickness of the solid target from bulk size to a few tens of nanometers, by reducing the size of the laser spot on the solid target, and finally, by reducing the lateral size of the bulk target. The interpretation of results was supported with numerical simulations of heat distribution inside the metal target in the three configurations. Surprisingly, we found that only the average size of NPs is affected by target thickness, whereas NPs polydispersity is reduced by confining the ablation geometry in transversal direction to the light propagation axis, that is, by decreasing transversal target size or laser spot size. In addition, we observed a strong dependence of yield versus target thickness, suggesting that targets below ∼0.1 mm should be avoided for optimal ablation rate. Taken together, these findings indicate that NPs formation mechanism changes with the depth of the ablated layer inside the bulk target and with the spatiotemporal temperature gradient in the material. By adding another piece to the puzzle of laser ablation synthesis in liquid solution, this study provides useful indications to improve the size distribution and productivity of laser-generated NPs.

Laser Ablation Synthesis in Solution Lasis of Functional Nanoparticles will be available on

Monodispersed CoPt alloy nanoparticles were synthesized by a pulsed laser ablation (PLA) technique coupled with a low-pressure operating differential mobility analyzer (LP-DMA). The CoPt alloy nanoparticles were generated by laser ablating a solid Co–Pt target. In CoPt alloy nanoparticles synthesized from a target with a Co composition of 75 at%, the nanoparticle surfaces were covered by an oxide layer and exhibited a core-shell structure. In contrast, no shell was observed in particles generated from a target with a Co:Pt ratio of 50:50 at%. According to an EDX analysis, the compositions of the individual nanoparticles were almost the same as that of the target material. Finally, the magnetic hysteresis loops of the CoPt alloy nanoparticles exhibited ferromagnetism.

Shafeev From Nanocrystal Synthesis to Nanomanufacturing: Laser Ablation in Liquid, P.


Laser Ablation Synthesis and Electron Transport Studies …

AB - Near infrared ultrafast pulsed laser is used to ablate pure metal and metal alloy targets in a vacuum chamber. We find that by optimizing the ablation conditions, as a direct result of ultrafast laser ablation, crystalline nanoparticles can be abundantly produced without intermediate nucleation and growth processes. Combining with different background gases, versatile structural forms can also be obtained for the nanocrystals. Using metal nickel as a sample material, we have produced Ni/NiO core/shell nanospheres and NiO nanocubes. We also study the production of alloy nanoparticles, which has been challenging in fabrication. We demonstrate production of nanoparticles containing up to three metal elements using ultrafast laser ablation. The laser ablation process is investigated using an ion probe in realtime. Nanoparticle samples are examined using atomic force microscopy and high resolution transmission electron microscopy for morphological, structural, and chemical analysis. This study provides a simple physical method for generating nanoparticles with a narrow particle size distribution, a high particle yield, versatile chemical compositions and structural forms.

Synthesis by Laser Ablation - YouTube

The areas of focus include basic thermodynamic and kinetic processes of laser ablation in liquids, and its applications in metal and metal oxides nanocrystals synthesis and semiconductor nanostructures fabrication.

The laser ablation synthesis ..

N2 - Near infrared ultrafast pulsed laser is used to ablate pure metal and metal alloy targets in a vacuum chamber. We find that by optimizing the ablation conditions, as a direct result of ultrafast laser ablation, crystalline nanoparticles can be abundantly produced without intermediate nucleation and growth processes. Combining with different background gases, versatile structural forms can also be obtained for the nanocrystals. Using metal nickel as a sample material, we have produced Ni/NiO core/shell nanospheres and NiO nanocubes. We also study the production of alloy nanoparticles, which has been challenging in fabrication. We demonstrate production of nanoparticles containing up to three metal elements using ultrafast laser ablation. The laser ablation process is investigated using an ion probe in realtime. Nanoparticle samples are examined using atomic force microscopy and high resolution transmission electron microscopy for morphological, structural, and chemical analysis. This study provides a simple physical method for generating nanoparticles with a narrow particle size distribution, a high particle yield, versatile chemical compositions and structural forms.