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Laser synthesis of iron nanoparticle for Fe doped hydroxyapatite coatings
摘要： Thin films of iron doped hydroxyapatite have been prepared by nanosecond Pulsed Laser Deposition (PLD). The composite target used for the deposition has been obtained by mixing commercial hydroxyapatite powder with iron-based nanoparticles produced by femtosecond laser ablation in liquid (LAL) (4% of iron nanoparticles). In fact, LAL technique allows to obtain metallic nanostructures without any toxic chemicals and reagents, with a green approach that is crucial for application in biological and medical technologies. Films have been prepared with substrate temperature growing from room temperature (RT) to 500 °C. The effect of deposition temperature on morphology, composition and structural properties of coatings has been investigated. Films deposited at higher temperature result dense and crystalline, they present microscale and nanoscale structures, an average surface roughness of 0.3 μm and magnetic properties suitable for biomedical applications.
关键词： PLD,Iron doped hydroxyapatite,Laser ablation in liquid,Regenerative orthopedic applications
更新于2025-09-23 15:23:52
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Effect of different hardness and melting point of the metallic surfaces on structural and optical properties of synthesized nanoparticles
摘要： The relations between macroscopic and microscopic characteristics of materials are of utmost importance for synthesis of multi-atomic structures with advanced properties. We analyze the influence of pulse duration, pulse energy and temperature of liquid on the process of formation of nanoparticles (NPs) of the metals (In, Sn, Zn and W) with different hardness and melting temperature by laser ablation in liquid environment. Composition, morphology dynamics and properties of nanoparticle suspensions are studied using TEM analysis and Z-scan technique. The nonlinear optical properties of NPs are analyzed at 800 and 400 nm using 60 fs and 200 ps pulses. We show that the temperature of liquid environment influences the formation of NPs and their nonlinear optical properties. In addition, pulse energy have little influence on the formation, morphology and size of NPs during ablation of low hardness and melting point metal (In). However, pulse duration plays a very important role during the formation of NPs, especially the ultra-short pulse has a positive effect on the preparation of NPs with smaller particle size.
关键词： nonlinear optical properties,metal nanoparticles,laser ablation in liquid
更新于2025-09-23 15:23:52
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Investigation the effect of laser ablation parameters in a liquid in order to reduce the pulse energy during laser shock peening
摘要： The features of laser shock peening technology was studied in relation to the physical processes occurring during and after laser treatment. The effect of laser parameters on the results of the process was investigated. It was shown that the reduce of the diameter of the laser spot while maintaining the intensity leads to a decrease in the effect of LSP. This phenomenon was studied from the point of view of the features of plastic deformation at various sizes of the treatment zone using the standard model for the LSP process. Besides the features of the development of a plasma plume during laser ablation in a liquid are considered. It was shown that the liquid determines the geometry of the plume evolution and the shock wave caused by it. The process parameters used and the results obtained are important for the development of low-energy LSP technology.
关键词： Surface treatment,Laser shock peening,Laser-produced plasmas,Laser ablation in liquid,Nickel alloys,Laser pulses,Lasers
更新于2025-09-23 15:21:01
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Laser Ablation of Stainless Steel in Water and Hexane: Characterization of Surface Modification and Nanoparticles for Various Applications
摘要： This work investigates the effect of a liquid medium on the roughness and the chemical composition of an ablated, stainless steel target, as well as on various properties of the laser-generated nanoparticles, such as absorption, hardness, and yield; in addition, some possible applications of laser ablation in both water and hexane are suggested. It is found that changing the liquid medium from hexane to distilled water not only changes the chemical composition of the target, but also reduces the mass ejected from the target by roughly 25%. Further, this change leads to a “smoother” ablation process and reduces the roughness of the target. Finally, mixed results were obtained when changing the liquid medium. Nanoparticle properties such as yield and absorption were found to be greatly affected, while mechanical properties, such as hardness, are not dependent on the liquid medium.
关键词： confined plasma,nanohardness,stainless steel,laser ablation in liquid,surface roughness
更新于2025-09-23 15:21:01
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Color tunable upconversion luminescence and optical thermometry properties of mixed Gd2O3:Yb3+/Ho3+/Er3+ nanoparticles prepared via laser ablation in liquid
摘要： The mixtures of Gd2O3:Yb3+/Er3+ and Gd2O3:Yb3+/Ho3+ nanoparticles were successfully prepared via pulsed laser ablation in liquid followed by solution mixing. Under excitation of 980 nm diode laser, tunable color from green to red emission was achieved. Based on the thermal linked energy levels, the temperature sensitive upconversion emission was observed. The fluorescence intensity ratio (FIR) of I513–530 nm/I530–580 nm increased as the elevation of temperature. The absolute sensitivity and relative sensitivity were derived from temperature dependent FIR. The results show that the mixture of Gd2O3:Yb3+/Er3+ and Gd2O3:Yb3+/Ho3+ nanoparticles are not only potential candidates for multicolor upconversion luminescence but also promising optical materials for non-contact optical thermometry.
关键词： Gd2O3 nanoparticles,Color tunable emission,Pulsed laser ablation in liquid,Optical thermometry,Upconversion luminescence
更新于2025-09-23 15:21:01
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Plasma charging effect on the nanoparticles releasing from the cavitation bubble to the solution during nanosecond Pulsed Laser Ablation in Liquid
摘要： The laser induced plasma during the nanosecond Pulsed Laser Ablation in Liquid (PLAL) plays a crucial role in the nanoparticles (NPs) formation and charging. It was demonstrated that during the plasma phase evolution, once the NPs are formed, they are charged with the excess of plasma electrons. Immediately after the plasma phase extinguishes, the NPs will be released in the induced vapor bubble, generated by the fast energy exchanges between the plasma and the liquid. The excess of charge in the NPs preserves them from the agglomeration during the bubble evolution and can induces an electrostatic pressure able to eject the particles outside the cavitation bubble. In this work, the plasma charging effect on the particle releasing in solution, during the bubble evolution, has been investigated. Temporal evolution of laser induced bubble on silver target immersed in water has been measured with the shadowgraph technique. Then, starting from the experimental bubble radius evolution, the releasing of the NPs from the cavitation bubble to the liquid has been modeled by comparing the electrostatic pressure of the charged NPs cloud and the pressure of the cavitation bubble. The following discussion proposes a new insight of the mechanism of NPs releasing in solution.
关键词： Laser Ablation Synthesis in Solution (LASIS),Cavitation bubble,NPs releasing,Pulsed Laser Ablation in Liquid (PLAL),NP formation
更新于2025-09-23 15:19:57
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Laser ablation of Ni in the presence of external magnetic field: Selection of microsized particles
摘要： The study presents results of nanosecond laser ablation of a Ni target in a liquid as a method of producing contamination-free micro- and nanosized colloidal structures. The ablation was performed in two liquids – double distilled water and ethanol, as their role on the characteristics of the ablated material is clarified. The laser ablation method in liquid was extended by applying an external magnetic field during the ablation process. A separation of micron and submicron particles from the nanoparticles in the colloidal solution is achieved by placing a substrate in the liquid, where the micron size structures are deposited under the action of the external magnetic field. At certain experimental conditions, the deposition of ordered one-dimensional microstructures on the substrate can be realized. The influence of different laser wavelengths on the features of the nanostructures dispersed in the liquid and microstructures deposited on the substrate was also investigated. On the basis of detailed analyses using Optical Microscopy, Scanning Electron Microscopy, Selected area electron diffraction, and Transmission Electron Microscopy the morphology, composition, and size distribution of the fabricated structures were studied. The presented method allows the fabrication of contamination-free micro- and nanostructures with potential applications in biotechnology, catalysis, and magneto-optics devices.
关键词： Laser ablation in liquid,Metal nanoparticles,Microstructures,Colloidal solution,External magnetic field
更新于2025-09-23 15:19:57
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Ultrasonic-Enhanced Fabrication of Metal Nanoparticles by Laser Ablation in Liquid
摘要： Laser ablation in liquid (LAL) is known to be a promising method for synthesizing metal nanoparticles. In this study, gold and silver nanoparticles were fabricated by ultrasonic-assisted LAL. Gold and silver plates were ablated using a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, with a wavelength of 532 nm and energy of 26.4 J cm?2, in distilled water in the presence and absence of an ultrasonic ?eld. The fabricated solution was analyzed with an ultraviolet?visible (UV?vis) nanoparticle colloidal spectrometer, a transmission electron microscope (TEM) with energy-dispersive X-ray spectroscopy (EDS), and ζ-potential measurement. The craters on the silver plates were analyzed by a scanning electron microscope (SEM), a laser microscope, and MATLAB to observe their morphology and calculate the volume to obtain the concentration of the fabricated nanoparticle solution. Optical emissions were observed to study the characteristics of the laser. The results showed that ultrasonic-assisted LAL has considerable potential for fabricating superior metal nanoparticles.
关键词： Silver nanoparticles,Ultrasonic-assisted,Nd:YAG laser,Laser ablation in liquid,Gold nanoparticles
更新于2025-09-19 17:13:59
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Synthesis and Deposition of Ag Nanoparticles by Combining Laser Ablation and Electrophoretic Deposition Techniques
摘要： Silver nanostructured thin films have been fabricated on silicon substrate by combining simultaneously pulsed laser ablation in liquid (PLAL) and electrophoretic deposition (ED) techniques. The composition, topography, crystalline structure, surface topography, and optical properties of the obtained films have been studied by energy dispersive X-ray spectroscopy (EDS), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and UV-visible spectrophotometry. The coatings were composed of Ag nanoparticles ranging from a few to hundred nm. The films exhibited homogenous morphology, uniform appearance, and a clear localized surface plasmon resonance (LSPR) around 400 nm.
关键词： pulsed laser ablation in liquid,electrophoretic deposition,silver nanoparticles
更新于2025-09-19 17:13:59
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Engineering the crystalline silicon surface by femtosecond laser processing in liquid: hierarchical micro/nanostructure and amorphization
摘要： Hierarchical micro/nanostructure surface structures with different spatial characteristics are achieved after irradiation of crystalline silicon via femtosecond (fs) laser pulses (800 nm, 120 fs, 1 kHz) with the sample submerged in ethanol. According to laser pulse energy and fabrication parameters (such as scanning speed and superimposing writing), a characteristic morphology evolution of ovoid-like smooth modified area, ripple-like, wave-like, and coral-like micro/nanostructures is demonstrated, and the underline principle is discussed. The amorphization of fs laser-modified area is verified and investigated by Raman spectroscope. These modified structures have potential applications in sensors, silicon photovoltaic cells, and sterilization.
关键词： topographical surface alterations,black silicon,laser ablation in liquid,femtosecond phenomena
更新于2025-09-19 17:13:59