Laser induced infrared spectral shift of the MgB2:Cr superconductor films

N S AlZayed; I V Kityk; S Soltan; A M El-Naggar; M Shahabuddin

doi:10.1016/j.saa.2014.10.068

Laser induced infrared spectral shift of the MgB2:Cr superconductor films

Spectrochim Acta A Mol Biomol Spectrosc. 2015 Feb 5:136 Pt C:1698-701. doi: 10.1016/j.saa.2014.10.068. Epub 2014 Oct 28.

Authors

N S AlZayed¹, I V Kityk², S Soltan³, A M El-Naggar⁴, M Shahabuddin¹

Affiliations

¹ Physics and Astronomy Department, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia.
² Electrical Engineering Department, Czestochowa University Technology, PL-42-201, Armii Krajowej 17, Czestochowa, Poland. Electronic address: iwank74@gmail.com.
³ Physics and Astronomy Department, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia; Max-Planck-Institut für Festkörperforschung, Heisenbergstr. 1, 70569 Stuttgart, Germany.
⁴ Physics and Astronomy Department, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia; Ain Shams University, Faculty of Science, Physics Dept., Abbassia, 11566 Cairo, Egypt.

PMID: 25467659
DOI: 10.1016/j.saa.2014.10.068

Abstract

During illumination of the MgB2:Cr2O3 films it was established substantial spectral shift of the infrared spectra in the vicinity of 20-50cm(-1). The excitations were performed by nanosecond Er:glass laser operating at 1.54μm and by microsecond 10.6μm CO2 laser. The spectral shifts of the IR maxima were in opposite spectral directions for the two types of lasers. This one observed difference correlates well with spectral shift of their critical temperatures. The possible explanation is given by performance of DFT calculations of the charge density redistribution and the time kinetics of the photovoltaic response. To understand the kinetics of the photoinduced processes the time kinetics of photoresponse was done for the particular laser wavelengths.

Keywords: High temperature superconductors; IR optical spectra; Photoinduced spectra.