A study on surface symmetry and interfacial enhancement of SrTiO_3 by second harmonic generation  

作　　者：ZHAO RuiQiang JIN KuiJuan GUO HaiZhong LU HuiBin YANG GuoZhen 

机构地区：[1]Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences

出　　处：《Science China(Physics,Mechanics & Astronomy)》2013年第12期2370-2376,共7页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Basic Research Program of China(Grant Nos.2012CB921403 and 2013CB328706);the National Natural Science Foundation of China(Grant No.11134012)

摘　　要：The symmetry of the surfaces of SrTiO3 and slightly Nb-doped SrTiO3 crystals was investigated by the optical reflected second harmonic generation technique. The good agreement between experimental and theoretical results of the second harmonic in- tensity dependence on the azimuth angle indicates that the SrTiO3 （001） surface is with 4ram symmetry and the Nb-doped SrTiO3 （111） surface with 3m symmetry. The measurements of the polarization dependent second harmonic intensity confirm that conclusion. The enhancement of the surface polarization in the structure of SrTiO3 capped La0.9Sr0.1MnO3 films compared with that in the La0.9Sr0.1MnO3 films has been obtained.The symmetry of the surfaces of SrTiO3and slightly Nb-doped SrTiO3crystals was investigated by the optical reflected second harmonic generation technique.The good agreement between experimental and theoretical results of the second harmonic intensity dependence on the azimuth angle indicates that the SrTiO3(001)surface is with 4mm symmetry and the Nb-doped SrTiO3(111)surface with 3m symmetry.The measurements of the polarization dependent second harmonic intensity confirm that conclusion.The enhancement of the surface polarization in the structure of SrTiO3capped La0.9Sr0.1MnO3films compared with that in the La0.9Sr0.1MnO3films has been obtained.

关 键 词：perovskite oxides SURFACE crystal symmetry second harmonic generation 

分 类 号：O469[理学—凝聚态物理]