Determination of the dielectric tensor function of crystals with arbitrary structure and orientation based on reflectance measurements

基于反射测量确定任意结构和取向晶体的介电​​张量函数

• 批准号: 229614732
• 负责人: Privatdozent Dr. Thomas Mayerhöfer
• 金额: --
• 依托单位: Leibniz-Institut für Photonische Technologien (IPHT)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/229614732?language=en
• 关键词: Determination; dielectric; tensor; function; crystals

The goal of the determination of oscillator parameters of a single crystal (dispersion analysis) is twofold. First the knowledge of these parameters can be used to analyze the structure properties relationships of the crystal and, second, as the parameters describe the function of the dielectric tensor in a certain spectral range, to calculate optical properties like reflectance, transmittance and scattering for single crystals and polycrystalline textured or randomly oriented materials.Recently, dispersion analysis based on the evaluation of reflectance measurements was extended to triclinic crystals and can therefore be applied to all crystals regardless their crystal structure. However, apart from the triclinic (and, trivially, cubic) single crystals, all other species need to be oriented prior to dispersion analysis. This orientation is usually carried out with help of X-ray diffraction methods. In a second step the oriented crystals need to be cut along and perpendicular to certain crystal axes and planes.The goal of the project is to develop a procedure for which an orientation step is not necessary and, eventually, also the determination of crystal structure and orientation is determined by reflectance spectroscopy with a subsequent dispersion analysis.In the first project phase dispersion analysis will be further developed to the point where it is possible to carry it out without prior orientation of a crystal if its crystal structure is known. The goal of the second phase consist of adapting and enhancing the oscillator model for triclinic crystals and thereby dispersion analysis in a way that knowledge of neither crystal structure nor orientation is a priori necessary to successfully conduct a dispersion analysis.

确定单晶的振荡器参数（色散分析）的目的是双重的。首先，这些参数的知识可以用于分析晶体的结构性质关系，并且第二，由于这些参数描述了介电张量在一定光谱范围内的函数，因此可以计算单晶和多晶织构或随机取向材料的光学性质，如反射率、透射率和散射。基于反射率测量的评估的色散分析被扩展到三斜晶体，因此可以应用于所有晶体，而不管它们的晶体结构。然而，除了三斜晶系（以及通常的立方晶系）单晶，所有其他种类都需要在色散分析之前进行取向。这种取向通常借助于X射线衍射方法进行。在第二步中，定向晶体需要沿着沿着和垂直于某些晶轴和晶面切割。该项目的目标是开发一种不需要定向步骤的程序，最终，此外，晶体结构和取向的测定是通过反射光谱法和随后的色散分析来确定的。在第一个项目阶段，色散分析将进一步发展到其中如果晶体结构已知，则可以在没有晶体的预先取向的情况下进行。第二阶段的目标包括调整和增强三斜晶体的振荡器模型，从而以一种既不需要晶体结构也不需要取向的先验知识来成功进行色散分析的方式进行色散分析。

项目成果

Complete dispersion analysis of single crystal yttrium orthosilicate

单晶原硅酸钇的完整色散分析

• DOI: 10.1016/j.vibspec.2016.01.004
• 发表时间: 2016
• 期刊: Vibrational Spectroscopy
• 影响因子: 2.5
• 作者: S. Höfer;R. Uecker;A. Kwasniewski;J. Popp;T. G. Mayerhöfer
• 通讯作者: T. G. Mayerhöfer

Dispersion analysis of arbitrarily cut uniaxial crystals

任意切割单轴晶体的色散分析

• DOI: 10.1016/j.vibspec.2015.03.004
• 发表时间: 2015
• 期刊: Vibrational Spectroscopy
• 影响因子: 2.5
• 作者: S. Höfer;R. Uecker;A. Kwasniewski;J. Popp;T. G. Mayerhöfer
• 通讯作者: T. G. Mayerhöfer

Complete dispersion analysis of single crystal neodymium gallate

单晶没食子酸钕的完整色散分析

• DOI: 10.1016/j.vibspec.2015.03.003
• 发表时间: 2015
• 期刊: Vibrational Spectroscopy
• 影响因子: 2.5
• 作者: S. Höfer;R. Uecker;A. Kwasniewski;J. Popp;T. G. Mayerhöfer
• 通讯作者: T. G. Mayerhöfer

Dispersion analysis of arbitrarily cut orthorhombic crystals.

任意切割斜方晶体的色散分析

• DOI: 10.1016/j.saa.2017.03.006
• 发表时间: 2017
• 期刊: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy
• 作者: Höfer;Ivanovski;Vladimir;Uecker;Reinhard;Kwasniewski;Albert;Jürgen;Mayerhöfer;Thomas G.
• 通讯作者: Thomas G.