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Titanium oxide nanoparticles (TiO 2 ) were produced by pulsed Nd:YAG laser ablation in water under the effect of an external magnetic eld. Various techniques such as X-ray diffraction (XRD), eld emission scanning electron microscopy (FESEM), energy Dispersive x-ray (EDX), transmission electron microscopy (TEM), UV-Vis spectroscopy, and Raman spectroscopy were used to characterize the TiO 2 nanoparticles.The XRD analysis of titanium oxide nanoparticles revealed that the synthesized nanoparticles were polycrystalline with mixed of tetragonal anatase and rutile TiO 2 . Scanning electron microscope shows the formation of spherical nanoparticles and the particles agglomeration decreases and the particle size from increases from 25nm to 35nm when the magnetic eld applied. The optical energy gap of TiO 2 nanoparticles decreased from 4.6eV to 3.4eV after using the magnetic eld during the ablation. Raman studies show the existence of ve vibration modes belong to TiO 2 . The antibacterial effect assay revealed a largest inhibition zone in S. aureus and E. coli, with a more potent effect for TiO 2 NPs prepared by magnetic eld when compared with that prepared without presence of magnetic eld.

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In this study, we have prepared aluminum oxide (Al 2 O 3 nanoparticles) NPs with size ranging from 50 to 90 nm by laser ablation of aluminum target in ethanol. The effect of laser fluence on the structural, morphological and optical properties of Al 2 O 3 was demonstrated and discussed. X-ray diffraction XRD results confirm that the synthesized Al 2 O 3 NPs are crystalline in nature. The sample prepared at 3.5 J/cm 2 /pulse exhibits single phase of c-Al 2 O 3 , while the XRD patterns of the nanoparticles synthesized at 5.3 and 7.5 J/cm 2 /pulse show the co-existence of the a-Al 2 O 3 and c-Al 2 O 3 phases. Nanostructured Al 2 O 3 films have been used as anti-reflecting coating and surface passivation layer to improve the photoresponse characteristics of silicon photodiode. The experimental data showed that the optical energy gap decreases from 5.3 to 5 eV as the laser fluence increases from 3.5 to 7.3 J/cm 2 . The lowest optical reflectivity was found for silicon photodiode deposited with a single layer of Al 2 O 3 prepared at 3.5 J/cm 2 /pulse. The effect of laser fluence on the refractive index and extinction coefficient of the nanostructured Al 2 O 3 film was studied. The photosensitivity of the silicon photodiode increased from 0.4 to 1.4 AW -1 at 800 nm after depositing Al 2 O 3 prepared at 3.5 J/cm 2 /pulse, followed by rapid thermal annealing at 400°C for 60 s.

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In this study, the authors reported the first synthesis process of silver iodide (AgI) nanoparticles (NPs) by pulsed laser ablation of the AgI target in deionised distilled water. The optical and structural properties of AgI NPs were investigated by using UV-vis absorption, X-ray diffraction, scanning electron microscope (SEM), energy dispersive X-ray, Fourier transform infrared spectroscopy, and transmission electron microscope (TEM). The optical data showed the presence of plasmon peak at 434 nm and the optical bandgap was found to be 2.6 eV at room temperature. SEM results confirm the agglomeration and aggregation of synthesised AgI NPs. TEM investigation showed that AgI NPs have a spherical shape and the average particle size was around 20 nm. The particle size distribution was the Gaussian type. The results showed that the synthesised AgI NPs have antibacterial activities against both bacterial strains and the activities were more potent against gram-negative bacteria.