Influence of transverse magnetic field on the properties of laser ablation produced nickel oxide nanoparticles

Abstract
Influence of transverse magnetic field on the nickel produced plasma plume and structural and optical properties of nickel oxide nanoparticles produced by pulsed laser ablation (PLA) method have been investigated experimentally. Ablation container was placed between the poles of permanent magnets. Strength of external magnetic field was controlled by the distance between magnets. The direction of the magnetic field was perpendicular to the direction of laser pulse propagation. 5 samples were synthesized in the presence of magnetic fields with different strengths in distilled water. Ablation was carried out by 1064 nm wavelength beam of pulsed Nd:YAG laser of 7 ns pulse width. Effects of external magnetic field on the properties of nickel oxide nanoparticles were characterized by X-ray diffraction patterns, field emission scanning electron microscope images, transmission electron microscope microimages, UV–Vis-NIR absorption spectra, dynamic light scattering patterns, FTIR and photoluminescence spectra. Furthermore, magnetic properties of synthesized nanoparticles were studied using their hysteresis curve which were recorded by vibrating sample magnetometer. Results show that with increasing the strength of external magnetic field, the intensity of XRD peaks of synthesized nanoparticles was increased while their size was decreased. Applying the external magnetic field caused the cyclotron motion of the charged particles in the plasma plume on the surface of target which increased their energy, and decreased their agglomeration.