摘要
用磁控溅射法制备了Ｐｔ／Ｃｏ／Ｐｔ／Ｎｉ 系列样品，其中Ｎｉ 层具有不同的厚度．通过测量样品的Ｋｅｒｒ 转角、椭偏率、折射率和吸收率，推算出了四个等效电导张量元σ１ｘｘ ，σ２ｘｘ ，σ１ ｘｙ，σ２ｘｙ 随Ｎｉ 层厚度的变化情况．再结合电导张量元与Ｋｅｒｒ 角的理论公式，分析了在Ｎｉ 层厚度的变化过程中，每一个电导张量元对Ｋｅｒｒ 角的贡献：发现在短波段σ２ ｘｙ 起主导作用，而在长波段四个电导张量元共同起作用．经分析认为这是由于在Ｎｉ 层的增厚过程中，Ｐｔ ５ｄ 带劈裂程度逐渐减小．与纯Ｐｔ／Ｃｏ 膜相比，在Ｎｉ 层的厚度为０－１０ —０－２３ ｎｍ 的范围内样品具有较低的居里温度和较高的Ｋｅｒｒ 角，这说明Ｐｔ／Ｃｏ／Ｐｔ／Ｎｉ 多层膜具有较高的应用价值．
Aseries of Pt/Co/Pt/Ni modulated multilayer with Nilayer thickness tNi ranging from 0 to 2-4 nm have been prepared by magnetronsputtering on Ptbuffer.Therelationsbetween conductivi tytensors σ1 xx ,σ2 xx ,σ1 xy ,σ2 xy and tNi werecalculated with measured valuesof Kerrrotation,ellip ticity,refractiveindex and absorptionindex.Andthen, θK= θK[σ1xx(tNi) ,σ2 xx(tNi) ,σ1 xy(tNi) , σ2 xy(tNi)] as a compound function of tNi wascalculated.It exhibitsthat,with the change of tNi, σ2 xyisthe majorfactortoinflunce θKatshort wavelengthand allofthefourconductivitytensorsare important atlong wavelengh,no oneis negligible. Wethinkthatthesplitting ofPt5d band,which originatesfrom spin orbit coupling,decreases with theincrease of tNi. The Curie temperature TC decreases monotonically with increasing tNi. For purpose of application, we show a range of tNi (0-3 —1-0 nm) ,in which TCislower while θKand Ris higherthan pure Pt/Co multilayers.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
1999年第S1期151-158,共8页
Acta Physica Sinica
基金
北京市自然科学基金!( 批准号:2982008)
