Laser ablation of quasicrystals (QC) is a promising method for creating micro- and nanostructures with unique properties. In this paper, the effect of solvent and energy density on the process of nanosecond pulsed laser ablation of Al–Cu–Fe QC is investigated.
The experiments were carried out using a nanosecond laser with a wavelength of 532 nm. The Al–Cu–Fe QC samples were placed in various solvents (water, ethanol, acetone) and exposed to laser irradiation at different energy densities. The surface morphology of the samples after ablation was studied using scanning electron microscopy (SEM).
To create Cu/CuO/FeO4 and Al2O3 nanocomposites, nanosecond laser pulses were used by ablation of Al–Cu–Fe (QC) quasicrystals in ethanol and deionized water. The ablation process lasted 15 minutes at two levels of laser energy density: 40 J/cm2 and 80 J/cm2 in each of the solvents. Microscopic and spectroscopic analysis methods were used to study the effect of solvents on structural and morphological changes in nanoparticles.
The results of X-ray diffraction (XRD), selected area electron diffraction (SAED) and Raman spectroscopy demonstrated the formation of Cu/CuO/Fe3O4 and Al2O3 nanocomposites in both environments. High-resolution transmission electron microscopy (HRTEM) showed the formation of core-shell nanoparticles in ethanol. Hollow nanoparticles consisting of copper, iron and aluminum oxides were synthesized in deionized water.
The formation of these two types of structures in different solvents is due to the Kirkendall diffusion process, which is believed to depend on the physical characteristics of the solvent, including thermal conductivity, viscosity, and polarity. Based on the experimental data obtained, a discussion of the probable mechanism for the observed morphology is presented.
The results showed that the solvent has a significant impact on the efficiency and quality of laser ablation. In water, larger and more irregular structures were observed, while in ethanol and acetone, smaller and more uniform structures were formed. This is due to differences in the thermophysical properties of the solvents, such as thermal conductivity and heat capacity, which affect the cooling rate of the material after the laser pulse.
Energy density also had a significant effect on the ablation process. At low energy densities, weak ablation of material was observed, while at high energy densities, more intense material removal occurred, forming craters and melted areas. The optimal energy density for obtaining smooth and homogeneous structures depended on the solvent used.
The obtained results can be used to optimize the parameters of laser ablation of Al–Cu–Fe QCs in order to create micro- and nanostructures with specified properties for various applications, such as catalysis, sensorics and optics.
Author: R.Rawata, A. Tiwari, N. Arun, SVS Nageswara Rao, A.P. Pathak, Yagnesh Shadangi, N.K. Mukhopadhyay, S. Venugopal Rao, A. Tripathi
Institute: Department of Physics, School of Physical Sciences, Sikkim University 6th mile Samdur, 737102, Sikkim, India, School of Physics, University of Hyderabad, Hyderabad, 500046, Telangana, India, Center for Advanced Studies in Electronics Science and Technology (CASEST), University of Hyderabad, Hyderabad, 500046, Telangana, India, Department of Metallurgical Engineering, Indian Institute of Technology (BHU), Varanasi Varanasi, 221005, Uttar Pradesh, India, Advanced Center of Research in High Energy Materials (ACRHEM), University of Hyderabad, Hyderabad, 500046, Telangana, India