Intrinsic nanoscale phase separation of bulk As2S3 glass
Intrinsic nanoscale phase separation of bulk As2S3 glass
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DOI：
10.1080/1478643031000151196
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发表时间：
2003-09-01
影响因子：
1.6
通讯作者：
Jackson, KA
中科院分区：
文献类型：
--
作者：
Georgiev, DG;Boolchand, P;Jackson, KA
拉曼散射表明，As 4S 4单体的振动模式首先出现在x = 0.38附近，其浓度随着x的增加而急剧增加，表明化学计量玻璃（x = 0.40）本质上是分相的，分为小的富As（As 4S 4）和大的富S团簇。拉曼活性振动模式的orpiment样和雄黄样纳米相的支持提供了从头计算密度泛函理论计算适当的集群。纳米级相分离提供了一个基础，了解全球最大的玻璃化转变温度T-g附近的x = 0.40，并从Arrhenius温度激活As 2S 3熔体粘度的偏离。
Raman scattering on bulk AsxS1-x glasses shows that vibrational modes of As4S4 monomer first appear near x = 0.38, and their concentration increases precipitously with increasing x, suggesting that the stoichiometric glass (x = 0.40) is intrinsically phase separated into small As-rich (As4S4) and large S-rich clusters. Support for the Raman-active vibrational modes of the orpiment-like and realgar-like nanophases is provided by ab-initio density functional theory calculations on appropriate clusters. Nanoscale phase separation provides a basis for understanding the global maximum in the glass transition temperature T-g near x = 0.40, and the departure from Arrhenius temperature activation of As2S3 melt viscosities.