Ni80Fe20-Nb-Ni80Fe20三层薄膜中基于杂散场的磁电阻机制
Stray-fields-based magnetoresistance mechanism in Ni80Fe20-Nb-Ni80Fe20 trilayers
摘要：
我们报告的运输和磁性的混合三层和双层，包括低自旋极化Ni80Fe20表现出平面内，但没有单轴各向异性和低Tc Nb。我们揭示了一个明显的磁阻效应。在我们的三层膜中，当达到超导状态时，磁阻表现出两个数量级的增加：从传统的正常状态值0.6%上升到1000%，温度低于Tc。相比之下，在双层中，影响仅是微小的，因为从正常状态下的3%仅增加到温度低于Tc时的70%。给出了纵向和横向磁分量的磁化数据。最重要的是，我们目前的数据不仅为正常状态的铌，但也在其超导状态。引人注目的是，这些数据表明，在其Tc SC以下，Nb夹层在外部Ni80Fe20层的影响下获得横向于外场的磁化分量。通过比较的运输和磁化数据，我们提出了一个候选机制，可以激发显着的磁阻效应中观察到的三层。外部Ni80Fe20层的足够静磁耦合是由杂散场激发的，杂散场由于它们获得接近磁性的多畴磁结构而在它们的整个表面中自然出现。采用原子力显微镜，以研究这种静磁耦合的可能性，可以促进界面粗糙度。参考双层，尽管仍然观察到单个Ni80Fe20层的磁化的面外旋转，但是在这些结构中，由于不存在第二Ni80Fe20层，所以不发生静磁耦合，使得观察到的磁阻峰值仅是适度的。
英文摘要：
We report on the transport and magnetic properties of hybrid trilayers and bilayers that consist of low spin-polarized Ni80Fe20 exhibiting in-plane but no uniaxial anisotropy and low-Tc Nb. We reveal a magnetoresistance effect that is pronounced. In our trilayers the magnetoresistance exhibits an increase of two orders of magnitude when the superconducting state is reached: from the conventional normal-state values 0.6 % it goes up to 1000 % for temperatures below Tc. In contrast, in the bilayers the effect is only minor since from 3% in the normal state increases only to 70 % for temperatures below Tc. Magnetization data of both the longitudinal and transverse magnetic components are presented. Most importantly, we present data not only for the normal state of Nb but also in its superconducting state. Strikingly, these data show that below its Tc SC the Nb interlayer under the influence of the outer Ni80Fe20 layers attains a magnetization component transverse to the external field. By comparing the transport and magnetization data we propose a candidate mechanism that could motivate the pronounced magnetoresistance effect observed in the trilayers. Adequate magnetostatic coupling of the outer Ni80Fe20 layers is motivated by stray fields that emerge naturally in their whole surface due to the multidomain magnetic structure that they attain near coercivity. Atomic force microscopy is employed in order to examine the possibility that such magnetostatic coupling could be promoted by interface roughness. Referring to the bilayers, although out-of-plane rotation of the magnetization of the single Ni80Fe20 layer is still observed, in these structures magnetostatic coupling does not occur due to the absence of a second Ni80Fe20 one so that the observed magnetoresistance peaks are only modest.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
