Thermal conductivity of Ge_xSb(As)_ySe _100-x-y glasses measured by Raman scattering spectra

We systematically measured thermal conductivity of Ge_xSb(As) ₁₀Se_90-x, Ge_xSb₁₅Se_85-x, and Ge_xSb(As)₂₀Se_80-x chalcogenide glasses by measuring their Stokes and anti-Stokes Raman scattering spectra and estimating the temperature raised by laser irradiation via the ratio of Stoke and anti-Stokes scattering cross-section. We aimed at demonstrating the viability of Raman scattering method for thermal conductivity measurements, and understanding the role of chemical composition in determining thermal conductivity of the chalcogenide glasses. We found that, while the values of the thermal conductivity measured in the paper are in a range from ~0.078 to 1.120Wm^-1K^-1 that are in agreement with those reported data in the literatures, thermal conductivity increases before it reaches a maximum at the glass with chemically stoichiometric composition, and then decreases with increasing Ge content. We ascribed the threshold behavior of the thermal conductivity to the demixing of the structural units like GeSe ₂, As₂Se₃ and Sb₂Se₃ from the main glass network. The present study demonstrated that Raman scattering method is simple and easy to measure thermal conductivity of the material.