温度作用下ANPZ太赫兹光谱非谐性机理  

Terahertz Spectral Anharmonicity of ANPZ Under Heating

作　　者：谢钗 段勇威 刘泉澄 邓琥[1,2] 张祺 武志翔[1] 魏文卿[1,2] 尚丽平 Xie Chai;Duan Yongwei;Liu Quancheng;Deng Hu;Zhang Qi;Wu Zhixiang;Wei Wenqing;Shang Liping(School of Information Engineering,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China;Tianfu Institute of Research and Innovation,Southwest University of Science and Technology,Chengdu 610299,Sichuan,China;Institute of Chemical Materials,Chinese Academy of Engineering Physics,Mianyang 621900,Sichuan,China)

机构地区：[1]西南科技大学信息工程学院,四川绵阳621010 [2]西南科大四川天府新区创新研究院,四川成都610299 [3]中国工程物理研究院化工材料研究所,四川绵阳621900

出　　处：《激光与光电子学进展》2024年第5期522-527,共6页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(62105271、62241304);西南科技大学博士基金(21zx7127)。

摘　　要：太赫兹光谱可表征晶体分子间弱相互作用,太赫兹光谱的非谐性机理为晶体宏观性质认知提供了微观基础。以2,6-二氨基-3,5-二硝基吡嗪(ANPZ)为对象,研究了温度作用下太赫兹光谱非谐性机理。通过光谱测量,获得ANPZ不同吸收峰的温度诱导非谐特性。通过密度泛函理论,对吸收的振动特性进行指认。对振动特性的分解结果表明:特定分子间氢键的软化是太赫兹光谱强非谐性的原因。进一步,基于声子和准简谐近似计算了ANPZ原子随温度的位移特性,并对上述分析结论进行了验证。研究表明:太赫兹光谱技术结合相关方法,可以深入分析温度作用下晶体内分子间氢键的响应规律,可为晶体宏观性质的认识提供科学分析手段。One of the benefits of using terahertz(THz)spectra in characterizing weak interactions is that their anharmonicity can help us to understand the macroscopic properties of crystals.In this study,2,6-diamino-3,5-dinitropyrazine(ANPZ)was adopted to analyze the anharmonic mechanism of terahertz spectra.First,the temperature-induced anharmonicity was obtained from the THz spectral measurement under heating.Next,density functional theory was used to identify the vibration properties of each absorption.Vibration mode decomposition was then employed to deeply analyze the origins of these anharmonic differences.The results show that the softening of the special intermolecular hydrogen bonding is responsible for the strong anharmonicity.Furthermore,the displacement properties of the atomic temperature factor calculated based on phonon and quasi-simple harmonic approximations also verify the above conclusion.The present study demonstrates that THz spectroscopy can provide insight into the response of hydrogen bonding under heating and can be used as a scientific analysis method for understanding the macroscopic properties of crystals.

关 键 词：光谱学 非谐性 模态分解 分子间氢键 温度 

分 类 号：O433[机械工程—光学工程]