元素取代对Ge-As(Sb)-Se玻璃转变阈值行为的影响  

Effect of elemental substitution on transition threshold behaviours of Ge-As(Sb)-Se glasses

作　　者：许思维 王训四 沈祥 Xu Si-Wei;Wang Xun-Si;Shen Xiang(College of Mathematics and Physics,Hunan University of Arts and Science,Changde 415000,China;Key Laboratory of Photoelectric Materials and Devices of Zhejiang Province,The Research Institute of Advanced Technologies,Ningbo University,Ningbo 315211,China)

机构地区：[1]湖南文理学院数理学院,常德415000 [2]宁波大学高等技术研究院,浙江省光电探测材料及器件重点实验室,宁波315211

出　　处：《物理学报》2024年第5期297-303,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:62004067);湖南省自然科学基金(批准号:2023JJ30438)资助的课题。

摘　　要：本文针对Sb取代As元素对Ge_(x)As(Sb)_(20)Se_(80-x)玻璃阈值行为的影响进行研究.对理想共价网络玻璃GexAs20Se80-x的玻璃转变温度、密度和折射率等物理参数进行了系统测量,在其平均配位数为2.4和2.67处验证了转变阈值的存在,这两个转变分别代表玻璃内部的共价网络结构从欠限制的松散状态到过限制的紧致状态的转变和从二维到三维紧致状态的转变.但是,当金属性更强的Sb取代As时,得到的非理想共价网络玻璃Ge_(x)Sb_(20)Se_(80-x)则会引起转变阈值的变化,转变阈值改变为化学计量组成.进一步利用拉曼散射技术对其结构进行表征,并将拉曼光谱通过分峰拟合分解成不同的结构单元的特征峰,它们各自的强度变化表现出相同的行为,这归因于As和Sb的原子半径差异较大所引起的化学效应以及Sb元素具有较强的离子特性.In this paper,We prepare two groups of glasses:one is Ge_(x)As(Sb)_(20)Se_(80-x) with x ranging from 5%to 32.5%,the other is Ge_(x)Sb_(20)Se_(80-x)with x spanning from 5%to 25%,by using the conventional melt-quench method,and investigate the effect of the elemental substitution of Sb for As on the threshold behaviors in Ge_(x)As(Sb)_(20)Se_(80-x)glasses.We are to understand to what extent the topological model and chemical order model can explain the correlation between physical properties and glass compositions,and how the chemical composition can affect the glass transition threshold.Glass transition temperature is measured by the differential scanning calorimeter(Mettler-Toledo,DSC1)with different scanning rates ranging from 5 K/min to 30 K/min under a uniform nitrogen gas flow of 50 mL/min,the glass density is measured by a Mettler H20 balance with a MgO crystal used as a reference.Samples of each glass composition are weighed five times and the average density is recorded.The refractive index of the glass at 1.5 um is measured by a Metricon Model 2010 prism coupler.Raman spectra are measured by a T64000 Jobin-Yvon-Horiba micro-Raman spectrometer equipped with a liquid-nitrogen-cooled CCD detector.The 830 nm laser line is used as an excitation source,and the laser power is kept as small as possible to avoid any photo-induced effects.The resolution of the spectrometer is about 0.5 cm^(-1).The systematic measurements of these physical parameters show that while the transition thresholds at MCN=2.4 and 2.67 are verified in the Ge-As-Se glasses with ideal covalent network,these two transitions represent the covalent network structure inside the glass from an under-constrained“floppy”network to an over-constrained“rigid”phase and from the two-dimensional to the three-dimensional“stressed rigid”phase respectively.However,when As is substituted by Sb,the the resulting Ge_(x)Sb_(20)Se_(80-x)glass with non-ideal covalent network will change its transition threshold,changing into the chemically stoichiometr

关 键 词：硫系玻璃 玻璃转变 拉曼散射 

分 类 号：TQ171.1[化学工程—玻璃工业]