Etude structurale et optique de matériaux composites

Abstract

This work is the development of single crystals KBr and KCl pure and doped with Nb crystallites was carried out by the drawing method according to the principle of Czochralski growth . The structural study and optical different matrices , alkali halides to know the effects of doping on their properties. The structural analysis of the samples prepared was carried out by the X-ray diffraction and IR spectroscopy and micro -Raman . XRD revealed the incorporation of Nb crystallite in the crystal matrix , and produces another Nano phase ( Nb2O5 ) . The μ -Raman and FT-IR spectroscopy to confirm the results of the characterization by X-ray diffraction as regards the presence of the phase Nb2O5 and existed the Nb- O chemical bond in the crystal matrices KBr and KCl . The optical absorption study for the nanocomposites prepared Nb / Nb and KBr / KCl show a transparent matrices in the Visible and Ultraviolet related field , When these matrices are doped with Nb2O5 nanocrystallites their optical gap decrease. The optical characterization radioluminescence for samples prepared shown that this low-intensity luminescence in the visible range when excited by radiation X.