The influence of Sb on glass‐forming ability of Ga‐containing As₂Se₃ glasses

Abstract

Effect of As to Sb substitution on glass-forming ability of As 2 Se 3 glass under Ga additions was comprehensively studied using optical spectroscopy in visible and IR regions, differential scanning calorimetry, X-ray diffraction as well as Raman scattering techniques. The crystallization processes enhanced by Ga additions to As 2 Se 3 glass were significantly suppressed under such As to Sb substitution. Following conventional synthesis, it was possible to substitute up to 50% of As by Sb within Ga y (As 0.40Àx Sb x Se 0.60 ) 100Ày cut-section without essential impact on glassy state, thus improving optical properties in the IR region by lowering the phonon energy. In the case of Ga y (As 0.28 Sb 0.12 Se 0.60 ) 100Ày cut-section, up to 8 at.% of Ga can be introduced without crystallization, whereas in case of Ga y (As 0.40 Se 0.60 ) 100Ày system, glass-forming ability is limited just up to 3 at.% of Ga. The prepared Ga 5 (As 0.28 Sb 0.12 Se 0.60 ) 95 glass composition was shown to be the richest in Ga keeping its vitreous state, good optical and thermodynamic properties allowing further rare-earth doping and fiber drawing.

Effect of Rare-Earth Doping on Free-Volume Nanostructure of Ga-Codoped Glassy (As/Sb)2Se3

“…In case of As-based ChG, this obstacle can be suppressed under partial As-to-Sb replacement [19]. This was a reason to turn towards nanostructurization in g-As-Se under Sb-modification.…”

“…One of the parasitic drawbacks of Ga-codoping nanostructurization concerns in increased crystallization ability of Ga-contained ChG under further RE doping, since both Ga and RE chalcogenides possess isostructural crystalline polymorphs [ 5 , 13 ]. In case of As-based ChG, this obstacle can be suppressed under partial As-to-Sb replacement [ 19 ]. This was a reason to turn towards nanostructurization in g-As-Se under Sb-modification.…”

“…One of the best resolutions is transferring to partial As to Sb replacement in g-As-Se, allowing optimal Ga-codoped g-Ga 2 (As 0.28 Sb 0.12 Se 0.60 ) 98 prepared by melt-quenching route like g-As 2 Se 3 or g-Ga 2 (As 0.40 Se 0.60 ) 98 [19]. …”

“…The third stage in nanostructurization is to modify the Ga-codoped ChG against possible parasitic devitrification (phase separation, crystallite nucleation, extraction, and growth), which can be activated in ChG under further RE doping. One of the best resolutions is transferring to partial As to Sb replacement in g-As-Se, allowing optimal Ga-codoped g-Ga 2 (As 0.28 Sb 0.12 Se 0.60 ) 98 prepared by melt-quenching route like g-As 2 Se 3 or g-Ga 2 (As 0.40 Se 0.60 ) 98 [ 19 ].…”

Nanoscale mechanism of rare‐earth doping in Ga‐codoped glassy As‐Sb selenides

“…It is known that partial As-by-Sb replacement within Ga y (As 0.40Àx Sb x Se 0.60 ) 100Ày cut-section reveals a stabilizing effect on ChG network suppressing parasitic crystallization processes caused by Ga addition. 27,28 That is why the Sbmodified As 2 Se 3 -based ChG will be examined, i.e., Gacodoped arsenic selenide g-Ga 2 (As 0.28 Sb 0.12 Se 0.60 ) 98 and g-Ga 2 (As 0.28 Sb 0.12 Se 0.60 ) 98 doped with 500 wppm of Pr 3+ .…”