Related Experiment Video
Updated: Mar 24, 2026

Low-energy Cathodoluminescence for OxyNitride Phosphors
Published on: November 15, 2016
Optical and Vibrational Spectra of CsCl-Enriched GeS2-Ga2S3 Glasses
Halyna Klym1, Ivan Karbovnyk2, Mariangela Cestelli Guidi3
1Lviv Polytechnic National University, 12 Bandery str., Lviv, 79013, Ukraine. halyna.i.klym@lpnu.ua.
Abstract:
Optical and FTIR spectroscopy was employed to study the properties of 80GeS2-20Ga2S3-CsCl chalcohalide glasses with CsCl additives in a temperature range of 77-293 K. It is shown that CsCl content results in the shift of fundamental absorption edge in the visible region. Vibrational bands in FTIR spectra of (80GeS2-20Ga2S3)100 - х (СsCl) x (x = 5, 10, and 15) are identified near 2500 cm(-1), 3700 cm(-1),, around 1580 cm(-1), and a feature at 1100 cm(-1). Low energy shifts of vibrational frequencies in glasses with a higher amount of CsCl can be caused by possible thermal expansion of the lattice and nanovoid agglomeration formed by CsCl additives in the inner structure of the Ge-Ga-S glass.
More Related Videos
Related Concept Videos
UV–Vis Spectroscopy: Molecular Electronic Transitions
Molecular Spectroscopy: Absorption and Emission
UV–Vis Spectroscopy of Conjugated Systems
One of the factors influencing λmax is the extent of conjugation in...
Atomic Spectroscopy: Absorption, Emission, and Fluorescence
Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...

