Raman spectroscopic analysis on the solubility mechanism of La3+ in GeS2-Ga2S3 glasses

다국어 초록 (Multilingual Abstract)

In comparison to other chalcogenide glasses, Ge-Ga-S glasses have the largest rare-earth solubility. Raman spectra of GeS_(2)-Ga_(2)S_(3) glasses contain two bands at 265 and 385 cm^(-1) which increased in intensity with the addition of Ga_(2)S_(3). These are associated with the vibration of Ge-Ge bonds and edge-shared GaS_(4) tetrahedra, respectively. Upon the addition of La_(2)S_(3) into GeS_(2)-Ga_(2)S_(3) glasses, intensities of these two bands decreased while a new band appeared at 375 cm^(-1) due to the vibration of tetrahedra with non-bridging sulfur(s). Dissociation of Ge-Ge bonds and edge-shared GaS_(4) tetrahedra through the addition of La_(2)S_(3) are responsible for the non-bridging sulfur formation. La^(3+) can be dissolved into the glass network as charge compensators for these non-bridging sulfurs. Since no such structural unit is present in glasses without Ga_(2)S_(3), this connection scheme and the structural modification in Ga-containing chalcogenide glasses seem to be crucial for an increase of La^(3+) solubility.

목차 (Table of Contents)

• 1. Introduction
• 2. Expwrimental procedure
• 2.1 Synthesis of glasses
• 2.2 Measurement of the Raman spectra
• 3. Results
• 4. Discussion
• 4.1 Structure of Ge-Ga-S glasses
• 4.2 Structure of Ge-Ga-La-S glasses
• 4.3 Proposed mechanism of La^(3+) solubility
• 5. Summary
• References