基于红外光谱实验与第一性原理计算的红柱石中结构水的研究  

First-Principle Calculation and Micro-FTIR Analysis of Structural Water in Andalusite

作　　者：张晓玲 黄欣 何开华[2] ZHANG Xiaoling;HUANG Xin;HE Kaihua(School of Arts and Media,Wuhan University of Engineering Science,Wuhan 430200,China;School of Mathematics and Physics,China University of Geosciences,Wuhan 430074,China)

机构地区：[1]武汉工程科技学院艺术与传媒学院,湖北武汉430200 [2]中国地质大学数学与物理学院,湖北武汉430074

出　　处：《宝石和宝石学杂志（中英文）》2022年第5期118-124,共7页Journal of Gems & Gemmology

基　　金：湖北自然科学基金:蓝晶石族矿物结构水的结合机理及其对相变的影响(2020CFB495)。

摘　　要：红柱石中的结构水对红柱石的密度、成分和弹性等物理化学性质有着重要影响。为探讨红柱石中含氢缺陷的结合机制以及结构水吸收峰的归属问题,本文用显微红外光谱(Micro-FTIR)分析和第一性原理计算,从晶体化学及结构缺陷性质的角度出发研究了红柱石中氢的结合机制,同时分析含氢缺陷的光谱。Micro-FTIR结果表明红柱石的主要吸收峰位于3749、3674、3659、3609、3599、3525、3517、3450 cm^(-1)和3444 cm^(-1)处。通过对缺陷形成能和能带的模拟计算发现,(4H)_(Si)复合缺陷模型比(AlH)_(Si)和(3H)_(Al)复合缺陷模型形成能更低,结构更稳定,(4H)_(Si)复合缺陷是红柱石中氢结合机制的优选模式。第一性原理计算得到红柱石含氢缺陷拉曼光谱,其峰值与本次红外光谱实验结果基本一致。对比红外光谱测试结果发现,(4H)_(Si)含氢缺陷几乎出现在所有的样品颗粒中,表明这一结合机制稳定性更好。红外光谱分析和第一性原理计算对结构羟基的归属进行指认,为矿物的实验研究提供理论依据,并为研究其他矿物的谱学归属问题提供了一种新思路。The structural water of andalusite critically influences the physical and chemical properties,such as the density,composition and elasticity of andalusite.In this study,micro Fourier transform infrared spectroscopy(Micro-FTIR)analysis and first-principle calculation are conducted to investigate the bonding mechanism and the spectra of defects models in andalusite.Micro-FTIR results show that the main absorption peaks of andalusite are 3749,3674,3659,3609,3599,3525,3517,3450 cm^(-1) and 3444 cm^(-1).The calculation results indicate that the formation energy of(4H)_(Si) defect model is lower than that of(AlH)_(Si) and(3H)_(Al) defect models.Moreover,the(4H)_(Si) complex defect is a preferential model in andalusite.Raman spectra of hydrogen defects in andalusite were calculated by the first principles,and it is basically consistent with the results of the infrared spectrum experiment.By comparing the results of infrared spectroscopy,it was found that(4H)_(Si) hydrogen defect almost appeared in all particles,indicating that this bonding mechanism is more stable.The attribution of structural hydroxyl groups by infrared spectrum analysis and first-principle calculation provides a theoretical basis for the experimental study of minerals and a new idea for the study of spectral attribution of other minerals.

关 键 词：红柱石 结构水 第一性原理计算 红外光谱 

分 类 号：TS93[轻工技术与工程]