High-pressure study on calcium azide(Ca(N_(3))_(2)):Bending of azide ions stabilizes the structure  

作　　者：武晓鑫 王颖健 李思琪 吕俊呈 王婧姝 杨丽华 张旗 刘艳清 张俊凯 贾洪声 Xiaoxin Wu;Yingjian Wang;Siqi Li;Juncheng Lv;Jingshu Wang;Lihua Yang;Qi Zhang;Yanqing Liu;Junkai Zhang;Hongsheng Jia(Key Laboratory of Functional Materials Physics and Chemistry (Ministry of Education),College of Physics,Jilin Normal University,Changchun 130103,China;The Joint Laboratory of MXene Materials,Jilin Normal University & Jilin 11 Technology Co.,Ltd.,Changchun 130103,China)

机构地区：[1]Key Laboratory of Functional Materials Physics and Chemistry (Ministry of Education),College of Physics,Jilin Normal University,Changchun 130103,China [2]The Joint Laboratory of MXene Materials,Jilin Normal University & Jilin 11 Technology Co.,Ltd.,Changchun 130103,China

出　　处：《Chinese Physics B》2024年第5期542-548,共7页中国物理B（英文版）

基　　金：Project supported financially by the Program for the Development of Science and Technology of Jilin Province,China(Grant Nos.YDZJ202301ZYTS382,YDZJ202201ZYTS316,and 20230101285JC);the National Natural Science Foundation of China(Grant No.11904128);the Program for Science and Technology of Education Department of Jilin Province,China(Grant Nos.JJKH20220438KJ and JJKH20220423KJ);the Program for the Jilin Provincial Development and Reform Commission Project(Grant No.2022C040-6)。

摘　　要：The high-pressure structure and elastic properties of calcium azide(Ca(N_(3))_(2))were investigated using in-situ highpressure x-ray diffraction and Raman scattering up to 54 GPa and 19 GPa,respectively.The compressibility of Ca(N_(3))_(2)changed as the pressure increased,and no phase transition occurred within the pressure from ambient pressure up to 54 GPa.The measured zero-pressure bulk modulus of Ca(N_(3))_(2)is higher than that of other alkali metal azides,due to differences in the ionic character of their metal-azide bonds.Using CASTEP,all vibration modes of Ca(N_(3))_(2)were accurately identified in the vibrational spectrum at ambient pressure.In the high-pressure vibration study,several external modes(ext.)and internal bending modes(ν_(2))of azide anions(N_(3)^(-))softened up to~7 GPa and then hardened beyond that pressure.This evidence is consistent with the variation observed in the F_(E)–f_(E)data analyzed from the XRD result,where the slope of the curve changes at 7.1 GPa.The main behaviors under pressure are the alternating compression,rotation,and bending of N_(3)^(-)ions.The bending behavior makes the structure of Ca(N_(3))_(2)more stable under pressure.

关 键 词：high pressure calcium azide azide anions 

分 类 号：TQ132.32[化学工程—无机化工]