Optical study of the structural change in ReS2 single crystals using polarized thermoreflectance spectroscopy.
Optical study of the structural change in ReS2 single crystals using polarized thermoreflectance spectroscopy.
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DOI：
10.1364/opex.13.000008
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发表时间：
2005-01
期刊：
影响因子：
3.8
通讯作者：
C. Ho
中科院分区：
文献类型：
--
作者：
C. Ho
在这份报告中，ReS2的光学性质的特点是使用偏振热反射（PTR）测量在25和300 K之间的温度范围内。以Br2为输运剂，采用化学气相输运法生长了ReS2单晶。晶化后的晶体形貌显示出两种不同的结构相。详细观察结晶固体，晶体相基本上可以分为两种不同类型的正常三斜层和四斜层结构。PTR实验是在光学偏振沿着和垂直于层状晶体和四晶晶体的晶体b轴的情况下进行的。从PTR测量的实验分析来看，ReS_2结构变化的发生很可能是由于原子键沿沿着轴的变形引起的，该轴平行于Re_4金刚石链。分析了ReS2不同结构相的带边跃迁随温度的变化关系。描述的过渡能和增宽参数的层状和tetrapheresReS2的温度变化的参数进行了评估和讨论。
In this report the optical properties of ReS2 are characterized using polarized thermoreflectance (PTR) measurements in the temperature range between 25 and 300 K. Single crystals of ReS2 were grown by chemical vapor transport method using Br2 as a transport agent. Crystal morphologies of the as-grown rhenium disulfides were shown to possess two different kinds of the structural phases after crystallization. Observing in detail on the crystallized solids, the crystal phases can be essentially divided into two distinct types of normal triclinic layer and tetragonal structure. The PTR experiments were done with optical polarizations along and perpendicular to the crystals' b-axis for both layer and tetragonal crystals. From the experimental analyses of PTR measurements the occurrence of structural change in ReS2 is mostly probable caused by the atomic bonding deformation along -axis, which is parallel to the Re4 parallelogram consisted diamond chains. Temperature dependences of the band-edge transitions for the different structural phases of ReS2 are analyzed. The parameters that describe temperature variations of the transition energies and broadening parameters for both layered and tetragonal ReS2 are evaluated and discussed.