Femtosecond laser induced nanostructuring of zirconium in liquid confined environment

Abstract

The surface, structural, and mechanical properties of zirconium after irradiation with Ti: sapphire laser (800 nm, 30 fs, 1 kHz) have been investigated. The zirconium targets were exposed for a varying number of laser pulses ranging from 500 to 2000 at a fixed fluence of 3.6 J/cm 2 corresponding to an intensity of 1.2×10 14 W/cm 2 in ambient environments of deionized water and propanol. A scanning electron microscope (SEM) was employed to investigate the surface morphology of the irradiated zirconium. The SEM analysis shows the formation of various kinds of features including nanoscale laser induced periodic surface structures (LIPSS), sponge like surface structure, flakes, conical structures, droplets, pores, and cavities. The energy dispersive x-ray spectroscopy (EDS) analysis exhibits the variation in chemical composition along with an enhanced diffusion of oxygen under both ambient conditions. The crystal structure and phase analyses of the exposed targets were explored by x-ray diffraction (XRD) and Raman spectroscopy techniques, respectively. The XRD analysis confirms the presence of various phases of zirconium hydride and zirconia after ablation in both de-ionized water and propanol. However, excessive hydrides are formed in the case of propanol. The Raman analysis supports the EDS and XRD results. It also reveals the presence of oxides (zirconia) after irradiation in both de-ionized water and propanol environments. The chemical reactivity of zirconium was significantly improved in the presence of liquids which were accountable for the growth of novel phases and modification in the chemical composition of the irradiated Zr. A nanohardness tester was employed to measure the nanohardness of the laser treated targets. The initial increase and then decrease in nanohardness was observed with an increase in the number of laser pulses in the de-ionized water environment. In the case of propanol, a continuous decrease in hardness was observed.

Laser-induced fabrication of highly branched CuS nanocrystals with excellent near-infrared absorption properties

“…The possibility of using laser light as a convenient and versatile tool for sculpting micro-and nano-structures has prompted the recent renewed interest in the multi-functional material systems. [1][2][3][4][5] Many interesting works, such as micronano scale ripples, [3] nano-sponges, [6] and subwavelength ripples, [5] have been reported by laser direct writing technique. In 2016, Terakawa et al demonstrated the construction of three-dimensional (3D) metal microstructures in biocompatible poly-based hydrogel by laser-induced photoreduction.…”

Characterization of KrF Excimer Laser Ablation of Cadmium in Different Liquids for Biomedical and Industrial Applications

“…This ripple formation can also be attributable to the interaction of ns laser radiation with the surface electromagnetic waves (SEW) formed during the laser interaction of the material [39]. The excitation of surface plasmon polaritons (SPPs) induces the periodic enhancement of local fields in the surface layer.…”

Study of Micro/Nano Structuring and Mechanical Properties of KrF Excimer Laser Irradiated Al for Aerospace Industry and Surface Engineering Applications

“…Fibrous structures like nanoscale ripples appear on the irradiated area of Figure 2a, along with droplets and cavities. Heating induced by laser causes thermal desorption, thermal ablation and explosive boiling after melting of the irradiated area which results in cavity formation [35] and the hydro-dynamical effects are responsible for the formation of droplets. With the increase of fluence, the fibrous structures are transformed to micro-cones exhibited in Figure 2c,d.…”

“…On the other hand, the reduced hardness can be related to crystal growth due to diffusion of O across the grain boundaries and tensile residual stresses causing enhancement in the cavity density and cavity size (Figure 4). From Figure 10, it is observed that the hardness variation directly depends on the crystallite size, O diffusion and presence of residual stresses [35].…”