用拉曼光谱测量GeSbSe玻璃的热导率*

摘要

We have measured the temperature raised by laser irradiation on the basis of difference between Stokes and anti-Stokes Raman scattering cross-sections, and further estimated the thermal conductivity of the material. GeSbSe glasses with compositions of GexSb10Se90−x, GexSb15Se85−x, and GexSb20Se80−x are systematically studied with the aim of verifying the practicability of the new method and understanding the role of chemical composition in determining the structure and thermal conductivity of the glasses. All of the results are in agreement with those reported on thermal conductivity measured by different methods in the literature. It is indicated that Raman scattering method is convenient and efficient to measure thermal conductivity of the materials. For each group of glasses, it is found that the thermal conductivity increases with increasing Ge concentration up to a transition point corresponding to the glass with chemically stoichiometric composition. We ascribe the threshold behaviour of the thermal conductivity to the demixing of the structural units from glass network.%本文根据斯托克斯和反斯托克斯拉曼光谱散射截面的不同,测量样品表面温度,并进一步提出了一种测量材料热导率的新方法。利用该方法系统地研究了GexSb10Se90-x, GexSb15Se85-x和GexSb20Se80-x三个系列的GeSbSe玻璃的热导率,从而证明该方法的实用性和可靠性,同时分析其化学组分对材料结构和热导率的影响。该方法测量获得的热导率与文献报道的热导率基本一致,表明拉曼光谱法测试材料的热导率简单、快捷,是一种实用的测量材料热导率的方法。结果表明每个系列硫系玻璃的热导率随着Ge浓度的增加而增加,在等于或近似化学配比组分处,硫系玻璃的热导率达到最大值,然后随着Ge含量的继续增加而降低。认为GeSbSe硫系玻璃热导率表现出的阈值现象归因于GeSbSe三元网络结构分离为二元结构的结果。