Vibrational modes in La2Zr2O7 pyrochlore irradiated with disparate electrical energy losses  

作　　者：Sheng-Xia Zhang Jie Liu Hua Xie Li-Jun Xu Pei-Pei Hu Jian Zen Zong-Zhen Li Li Liu Wen-Si Ai Peng-Fei Zhai 张胜霞;刘杰;谢华;徐丽君;胡培培;曾健;李宗臻;刘丽;艾文思;翟鹏飞(Institute of Modern Physics,Chinese Academy of Sciences(CAS),Lanzhou 730000,China;Fundamental Science on Nuclear Wastes and Environmental Safety Laboratory,Southwest University of Science and Technology,Mianyang 621010,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]Institute of Modern Physics,Chinese Academy of Sciences(CAS),Lanzhou 730000,China [2]Fundamental Science on Nuclear Wastes and Environmental Safety Laboratory,Southwest University of Science and Technology,Mianyang 621010,China [3]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Chinese Physics B》2019年第11期246-250,共5页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.11705246,11675233,and 11690041);the Natural Science Foundation of Gansu Province,China(Grant No.17JR5RA316)

摘　　要：Polycrystalline samples of La2Zr2O7 pyrochlore are irradiated by different energetic heavy ions to investigate the dependence of the vibrational mode variations on the irradiation parameters. The applied electronic energy loss(d E/dx)e increases from about 5.2 keV/nm to 39.6 keV/nm. The ion fluence ranges from 1× 10^11 ions/cm^2 to 6× 10^15 ions/cm^2.Vibrational modes of irradiated pyrochlore are analyzed by using Raman spectrum. Infrared active modes F1 uat 192, 308,and 651 cm^-1 appear in Raman spectra, and the F2 gband at 265 cm-1 rises up due to the irradiation by 200-MeV Kr ions with(d E/dx)e of 16.0 keV/nm. Differently, for the pyrochlore irradiated by 1750-MeV Bi ions with(d E/dx)e of 39.6 keV/nm, in spite of the appearance of infrared active mode F1 u651 cm^-1, the amorphous structure occurs according to the vibrational mode variations of pyrochlore irradiated at higher ion fluences. Amorphous tracks are observed in the samples, which confirm the occurrence of pyrochlore–amorphous transition in pyrochlore irradiated with(d E/dx)e of 39.6 keV/nm.Polycrystalline samples of La2Zr2O7 pyrochlore are irradiated by different energetic heavy ions to investigate the dependence of the vibrational mode variations on the irradiation parameters. The applied electronic energy loss（d E/dx）e increases from about 5.2 keV/nm to 39.6 keV/nm. The ion fluence ranges from 1× 1011 ions/cm2 to 6× 1015 ions/cm2.Vibrational modes of irradiated pyrochlore are analyzed by using Raman spectrum. Infrared active modes F1 uat 192, 308,and 651 cm-1 appear in Raman spectra, and the F2 gband at 265 cm-1 rises up due to the irradiation by 200-MeV Kr ions with（d E/dx）e of 16.0 keV/nm. Differently, for the pyrochlore irradiated by 1750-MeV Bi ions with（d E/dx）e of 39.6 keV/nm, in spite of the appearance of infrared active mode F1 u651 cm-1, the amorphous structure occurs according to the vibrational mode variations of pyrochlore irradiated at higher ion fluences. Amorphous tracks are observed in the samples, which confirm the occurrence of pyrochlore–amorphous transition in pyrochlore irradiated with（d E/dx）e of 39.6 keV/nm.

关 键 词：PYROCHLORE HEAVY ion IRRADIATION VIBRATIONAL spectra phase transition 

分 类 号：O61[理学—无机化学]