Skip to main content Accessibility help
×
Home

Spatial confinement effects employed by metallic blocker and Ar gas pressures on laser-induced breakdown spectroscopy and surface modifications of laser-irradiated Mg

  • A. Hayat (a1), S. Bashir (a1), M. S. Rafique (a2), R. Ahmed (a1), M. Akram (a1), K. Mahmood (a1), A. Zaheer (a1), T. Hussain (a1) and A. Dawood (a1)...

Abstract

Spatial confinement effects on plasma parameters and surface morphology of laser-ablated Mg are studied by introducing a metallic blocker as well as argon (Ar) gas at different pressures. Nd: YAG laser at various fluences ranging from 7 to 28 J/cm2 was employed to generate Mg plasma. Confinement effects offered by metallic blocker are investigated by placing the blocker at different distances of 6, 8, and 10 mm from the target surface; whereas spatial confinement offered by environmental gas is explored under four different pressures of 5, 10, 20, and 50 Torr. Laser-induced breakdown spectroscopy analysis revealed that both plasma parameters, that is, excitation temperature and electron number density initially are strongly dependent upon both pressures of environmental gases and distances of blockers. The maximum electron temperature of Mg plasma is achieved at Ar gas pressure of 20 Torr, whereas maximum electron number density is achieved at 50 Torr. It is also observed that spatial confinement offered by metallic blocker is responsible for the significant enhancement of both electron temperature and electron number density of Mg plasma. Maximum values of electron temperature and electron number density without blocker are 8335 K and 2.4 × 1016 cm−3, respectively, whereas these values are enhanced to 12,200 K and 4 × 1016 cm−3 in the presence of blocker. Physical mechanisms responsible for the enhancement of Mg plasma parameters are plasma compression, confinement and pronounced collisional excitations due to reflection of shock waves. Scanning electron microscope analysis was performed to explore the surface morphology of laser-ablated Mg. It reveals the formation of ripples and channels that become more distinct in the presence of blocker due to plasma confinement. The optimum combination of blocker distance, fluence and Ar pressure can identify the suitable conditions for defining the role of plasma parameters for surface structuring.

Copyright

Corresponding author

Address correspondence and reprint requests to: A. Hayat, Centre for Advanced Studies in Physics, GC University, Lahore, Pakistan. E-mail: asmahayat@gcu.edu.pk

References

Hide All
Bashir, S., Rafique, M.S. & Husinsky, W. (2009). Surface topography (nano-sized hillocks) and particle emission of metals, dielectrics and semiconductors during ultra-short-laser ablation: Towards a coherent understanding of relevant processes. Appl. Surf. Sci. 255, 83728376.
Bauerle, D. (2011). Laser Processing and Chemistry. Heidelberg: Springer-Verlag.
Chen, F.F., Su, X.J. & Zhou, W.D. (2015). Effect of parameters on Si plasma emission in collinear double-pulse laser-induced breakdown spectroscopy. Front. Phys. 10, 104207–10412.
Chorlis, C.H., Reader, J., Wiese, W.L. & Martin, G.A. (1980). Wavelengths and Transition Probabilities for Atoms and Atomic Ions. Washington, DC: National Bureau of Standards.
Cremer, D.A. & Radziemski, L.J. (2006). Handbook of Laser-Induced Breakdown Spectroscopy. Chichester: Wiley.
Dawood, A., Bashir, S., Akram, M., Hayat, A., Ahmad, S., Iqbal, M.H. & Kazmi, A.H. (2015). Effect of nature and pressure of ambient environments on the surface morphology, plasma parameters, hardness, and corrosion resistance of laser-irradiated Mg-alloy. Laser Part. Beams 33, 315330.
Dawood, M.S. & Margot, J. (2014). Effect of ambient gas pressure and nature on the temporal evolution of aluminium laser-induced plasmas. AIP Adv. 4, 03711110371113.
Farid, N., Harilal, S., Ding, H. & Hassanein, A. (2014). Emission features and expansion dynamics of nanosecond laser ablation plumes at different ambient pressures. J. Appl. Phys. 115, 033107033116.
Fried, D., Khshida, T., Reck, G.P. & Rothe, E.W. (1992). Effect of electric field associated with a laser induced pulsed discharge on the ablation-generated plumes of YBa2Cu3O7-X. J. Appl. Phys. 72, 11131125.
Fu, Y., Hou, Z. & Wang, Z. (2016). Physical insights of cavity confinement enhancing effects in laser-induced breakdown spectroscopy. Opt. Exp. 24, 30553066.
Gao, X., Liu, L., Song, C. & LIN, J. (2015). The role of spatial confinement on nanosecond YAG laser-induced Cu plasma. J. Phys. D: Appl. Phys. 48, 1752051–1552056.
Harilal, S.S., Bindhu, C.V., Nampoori, V.P.N. & Vallabhan, C.P.G. (1998). Influence of ambient gas on the temperature and density of laser produced carbon plasma. Appl. Phys. Lett. 72, 167169.
Harilal, S.S., Farid, N., Freeman, J.R., Diwakar, P.K., Lahaye, N.L. & Hassanein, A. (2014). Background gas collisional effects on expanding fs and ns laser ablation plumes. Appl. Phys. A 117, 319326.
Hayat, A., Bashir, S., Rafique, M.S., Akram, M., Mahmood, K., Iqbal, S., Dawood, A. & Arooj, (2016). Spectroscopic and morphological study of laser ablated Titanium. Opt. Spectrosc. 121, 19.
Huang, F., Liang, P., Yang, X., Cai, H., Wu, J., Ying, Z. & Sun, J. (2015). Confinements effects of shock waves on laser-induced plasma from graphite target. Phys. Plasmas 22, 063509063516.
Iqbal, S., Rafique, M.S., Anjum, S., Hayat, A. & Iqbal, N. (2012). Impact of X-ray irradiation on PMMA thin films. Appl. Surf. Sci. 259, 853860.
Khalil, A.A.I. & Gondal, M.A. (2012). Effect of ambient conditions on laser induced breakdown spectroscopy. Laser Phys. 22, 17711779.
Khumaeni, A., Akaoka, K., Miyabe, M. & Wakaida, I. (2016). The role of microwaves in the enhancement of laser-induced plasma emission. Front. Phys. 11, 11420921142099.
Liu, L., Huang, X., Li, S., Lu, Y., Chen, K., Jiang, L., Silvain, J.F. & Lu, Y.F. (2015). Laser-induced breakdown spectroscopy enhanced by a micro torch. Appl. Opt. 23, 1504715057.
Rumsby, P. & Paul, J.W.M. (1974). Temperature and density of an expanding laser produced plasma. J. Plasma Phys. 16, 247251.
Scaffidi, J., Pender, J., Pearman, W., Goode, S.R., Colston, B.W., Carter, J.C. & Angel, S.M. (2003). Dual-pulse laser-induced breakdown spectroscopy with combinations of femtosecond and nanosecond laser pulses. Appl. Opt. 42, 60996106.
Shakeel, H., Arshad, S., Haq, S.U. & Nadeem, A. (2016). Electron temperature and density measurements of laser induced germanium plasma. Phys. Plasmas 23, 05350410535049.
Verhoff, B., Harilal, S.S., Freeman, J.R., Diwakar, P.K. & Hussanein, A. (2012). Dynamics of femto-and nanosecond laser ablation plumes investigated using optical emission spectroscopy. J. Appl. Phys. 112, 09330310933039.
Zhong, S.L., Lu, Y., Kong, W.J., Cheng, K. & Zheng, R. (2016). Quantitative analysis of lead in aqueous solutions by ultrasonic nebulizer assisted laser induced breakdown spectroscopy. Front. Phys. 11, 11420211142029.

Keywords

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed