Irreversible thermostructural transformations in amorphous As 2 S 3 films: A light-scattering study
Irreversible thermostructural transformations in amorphous As 2 S 3 films: A light-scattering study
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DOI：
10.1103/physrevb.15.2084
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发表时间：
1977-02
影响因子：
3.7
通讯作者：
S. Solin;G. Papatheodorou
中科院分区：
文献类型：
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作者：
S. Solin;G. Papatheodorou
记录了S玻璃蒸发薄膜在玻璃化转变温度下退火前后的偏振光谱，并与大块玻璃的相应光谱进行了比较。原始薄膜的光谱由几个尖锐的分子带叠加在网状的连续统一体上，这是大块玻璃的特征，而退火薄膜只产生大块玻璃的光谱，尽管有一些残留的非化学计量比的迹象。这些结果直接证明了蒸发薄膜中的不可逆热结构转变(或等价的光结构转变)是通过DeNeufville，Moss和Ovshinsky提出的亚稳分子玻璃的聚合进行的。获得了气态蒸气在S液体上的偏振拉曼光谱，表明存在多种气态分子物种。蒸发的无定形薄膜的分子成分也很复杂，但与蒸气的分子成分不同，这表明沉积本身引入了一些结构变化。
Polarized spectra of evaporated thin films of ${\mathrm{As}}_{2}$${\mathrm{S}}_{3}$ glass have been recorded before and after annealing at the glass transition temperature and compared with the corresponding spectrum of the bulk glass. The spectra of virgin films consist of several sharp molecular bands superposed on a networklike continuum which is characteristic of the bulk glass, whereas annealed films yield only the bulk glass spectrum albeit with some indication of residual nonstoichiometry. These results are direct evidence that irreversible thermostructural transformations (or equivalent photostructural transformations) in evaporated ${\mathrm{As}}_{2}$${\mathrm{S}}_{3}$ films proceed through polymerization of a metastable molecular glass as suggested by deNeufville, Moss, and Ovshinsky. The polarized Raman spectra of the vapors over ${\mathrm{As}}_{2}$${\mathrm{S}}_{3}$ liquid have been obtained and indicate the presence of serveral gaseous molecular species. The molecular constituency of the evaporated amorphous film is also complex but distinct from that of the vapor, an indication that deposition itself introduces some structural alterations.