Pressure effects on the absorption spectra of Na doped in solid Ar  

作　　者：CUI Tian1, HE Wenjiong1, YIN Hongwei1, MA Yanming1, CHEN Changbo1, ZOU Guangtian1, WEI Mengfu2 & CHEN Changan2 1. National Laboratory of Superhard Materials, Jilin University, Changchun 130012, China 2. China Academy of Engineering Physics, Box 919-71, Mianyang 621900, China 

出　　处：《Science China(Physics,Mechanics & Astronomy)》2004年第5期550-560,共11页中国科学：物理学、力学、天文学（英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(Grant No.10276016);the Innovation Fund of Jilin University;2003 EYTP of Ministry of Education of China.

摘　　要：In this work, the pressure influence on the absorption spectra of Na in solid Ar for various trapping sites is extensively investigated at T = 10 K and in the pressure range from 0 to 2.4 GPa by using Monte Carlo method with a constant pressure ensemble (NPT). For the trapping sites of nv = 1, 2, the absorption spectral widths increase progressively, the absorption peaks and the centroid spectral shift (CSS) tend to have a red shift with pressure increasing, even though there is no local structural symmetry change around Na atom caused by pressure. Highly symmetrical trapping site structure (nv = 1) determines a highly symmetrical triplet absorption feature at a low pressure. With the increase in pressure, the action from the Ar crystal field on the three energy levels of the 3p excited state of Na atom increases, resulting in the overlap of the three peaks. Low symmetrical trapping site structure (nv = 2) yields a low symmetrical triplet absorption pattern in which a large separation between the single?and the double?peaks exists at a low pressure. With the increase in pressure, the splitting between the singlet and the doublet increases, and the doublet merges as the pressure is larger than 2.4 GPa.In this work, the pressure influence on the absorption spectra of Na in solid Ar for various trapping sites is extensively investigated atT=10 K and in the pressure range from 0 to 2.4 GPa by using Monte Carlo method with a constant pressure ensemble (NPT). For the trapping sites ofn v=1, 2, the absorption spectral widths increase progressively, the absorption peaks and the centroid spectral shift (CSS) tend to have a red shift with pressure increasing, even though there is no local structural symmetry change around Na atom caused by pressure. Highly symmetrical trapping site structure (n v=1) determines a highly symmetrical triplet absorption feature at a low pressure. With the increase in pressure, the action from the Ar crystal field on the three energy levels of the 3p excited state of Na atom increases, resulting in the overlap of the three peaks. Low symmetrical trapping site structure (n v=2) yields a low symmetrical triplet absorption pattern in which a large separation between the “single” and the “double” peaks exists at a low pressure. With the increase in pressure, the splitting between the singlet and the doublet increases, and the doublet merges as the pressure is larger than 2.4 GPa.

关 键 词：MONTE Carlo  simulation  ABSORPTION spectra  DOPED system  pressure effect. 

分 类 号：O433.51[机械工程—光学工程]