Synthesis and properties of Ge-Sb-S: NdCl3 glasses

Abstract

High purity (GeS2)8−x (Sb2S3)20(NdCl3)x x=0, 0.01, 0.1, 0.5, glasses were prepared and their optical properties determined. The Ge-Sb-S system dissolves up to 0.5 mol.% of NdCl3 and still forms stable glasses. The structure of these glasses is formed by interconnected GeS4 tetrahedra and SbS3 pyramids as it follows from the Raman spectra. The glasses are optically well transparent in the range from 15400 cm−1 to 1000 cm−1. Doping with Nd creates new absorption bands which can be assigned to electron transfer from the 4 I 9/2 level to 2 G 5/2, 2 G 7/2, 2 H 11/2, 4 F 9/2, 4 F 7/2, 4 S 3/2, 2 H 9/2, 4 F 5/2, 4 F 3/2, 4 I 13/2 and 4 I 11/2 levels. The oscillator strengths and Judd-Ofelt parameters were evaluated. Their values are close to the values of those for Nd3+1 in another chalcogenide hosts. The long-wavelength absorption edge was found near 1000 cm−1 and is due to multiphonon Ge-S and Sb-S vibrations. In doped glasses, several broad luminescence bands near 890, 1080, 1370, and 1540 nm were found. They can be attributed to the transitions from 4 F 3/2 to 4 I 9/2, to 4 I 11/2, to 4 I 13/2 and 4 I 15/2 electron levels. The first luminescence band was excited also by 1064-nm line and represents probably the upconversion of light.