三方晶系的非线性磁光克尔谱及其表面磁化强度取向的效应

NONLINEAR MAGNETO-OPTICAL KERR SPECTROSCOPY AND EFFECT OF DIRECTION OF MAGNETIZATION ON SURFACE FOR THE TRIGONAL STRUCTURE

本文计算了三方结构不同表面和不同磁化强度取向下的 χ( 2 ) 、SHG、MSHG及非线性克尔旋转角 Φ( 2 )k,a.结果表明 ,SHG和 Φ( 2 )k,a值非常灵敏地依赖于薄膜的表面及磁化强度的取向 ;三方结构的 SHG、Φ( 2 )k,a与 fcc、bcc和 hcp结构的相比有很大的差异 ,这表明结构对非线性磁光效应有重要的影响 ;当 M∥X、Y轴时 ,MSHG信号很明显 ,这表明可通过 A值的测量来研究磁性薄膜表面的磁畴结构以及取向 .

second-harmonic generation (SHG) ,magnetically induced second-harmonic generation (MSHG) and nonlinear magneto-optical Kerr rotation angleΦ( 2 )k,α for trigonal crystal structure have been derived.The calculated results reveal as follows:SHG andΦ( 2 )k,αdepend sensitively on surfaces and directions of magnetization of thin magneticfilms;SHG andΦ( 2 )k,αof trigonal crystal structure are differ- entfrom ones of fcc,bcc and hcp structures,which means structure of crystal has an importantinflu- ence on nonlinear magneto-optical effect;As M∥ X、Y,the values of MSHG are obvious,which means thatby measuring the value of MSHG(A) ,the structureand direction of magnetic domain can bestud- ied.