Co/Cu多层膜层间耦合作用的调节

【作者】 王利东；

【导师】 姜宏伟；

【作者基本信息】 首都师范大学 ， 凝聚态物理， 2008， 硕士

【摘要】 多层膜的层间耦合作用在巨磁电阻效应的自旋电子学器件中有着广泛应用,已经成为国际研究的热点。在GMR和TMR的物理、材料和技术应用中,铁磁层和反铁磁层间的耦合作用起着至关重要的作用。本文研究了[Co/Cu]多层膜体系的耦合作用和磁性能及其影响因素。采用了磁控溅射的方法制备了Fe（50（?））/[Co/Cu] ₃₀多层膜,多层膜在层间耦合作用振荡的第二峰时的磁电阻能达到15%,退火处理后可以达到18%。没有Fe缓冲层时的磁电阻比有Fe缓冲层时的磁电阻要小,缓冲层影响薄膜的生长和织构,从而影响多层膜的层间耦合作用。为了提高多层膜的磁灵敏度,在Fe（50（?））/[Co/Cu]₃₀多层膜的隔离层（Cu）中掺入磁性元素Co,引入与相邻Co层之间反铁磁的RKKY作用相竞争的直接的铁磁耦合作用,降低了相邻Co层间的交换耦合作用。层间耦合作用强度由掺入8at%Co时的0.05erg/cm2降到掺入₃₀at%Co时的0.025erg/cm2,饱和磁场有所降低,从而提高了多层膜对外磁场变化的灵敏度。对一组Fe（50（?））/[Co/Co(₃₀at%)Cu（70at%）]₃₀样品在₃₀0℃进行两个小时退火处理,测量XRD结果显示,多层膜织构得到优化,层间反铁磁耦合作用变弱。更多还原

【Abstract】 Exchange coupling in multilayers across their common interface, due to its intriguing physics and the key role in giant magnetoresistance effect spintronic devices, has attracted a great deal of attention in recent years. Ferromagnetic and antiferromagnetic exchange coupling play an important part in GMR and TMR application in physics ,material and technology.In this dissertation, we studied on the exchange coupling and magnetic fuction in Co/Cu mutilayers system.The Fe（50（?））/[Co/Cu] ₃₀ multilayers have been prepared by using DC magnetron sputtering. The GMR of this multilayers could reach fifteen percent at the second peak of interlayer exchange coupling,and reach eighteen percent after annealing.The GMR of multilayers without Fe buffer is less than the one with Fe buffer,and for it’s effect on the growth and configuration of films the interlayer exchange coupling have been affected.For the sake of increase the sensitivity to magnetic field, magnetic element for instant Co have been blended in the spacer Cu in Fe（50（?））/[Co/Cu]₃₀ multilayers and direct ferromagnetic coupling has been introduced to compete with the antiferromagnetic RKKY of adjacent Co layers,so exchange coupling in adjacent Co layers have been depressed.The interlayer coupling is 0.05erg/cm2 with 8at% Co blending and 0.025erg/cm2with 8at% Co blending,so it have depressed with increasing the Co quantity. By changing the amount of magnetic element in the spacers,the saturation magnetic field has been weaken in multilayers and multilayers become more sensitive to external magnetic field.If 8at% Co was blended in the multilayers,the sensitivity of the multilayers to external magnetic field have improved 25% in saturation magnetic field.The sample Fe（50（?））/[Co/Co（x）Cu（1-x）]₃₀ has been disposed by annealing.After two hours annealing,the structure of multilayers have been optimized by XRD and the antiferromagnetic coupling have been weaken.更多还原