Satchell N, Gupta S, Maheshwari M, Shepley P M, Rogers M, Cespedes O, Burnell G
School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT UK.
Sci Rep. 2023 Aug 1;13(1):12468. doi: 10.1038/s41598-023-37825-3.
Ferromagnetic films with perpendicular magnetic anisotropy are of interest in spintronics and superconducting spintronics. Perpendicular magnetic anisotropy can be achieved in thin ferromagnetic multilayer structures, when the anisotropy is driven by carefully engineered interfaces. Devices with multiple interfaces are disadvantageous for our application in superconducting spintronics, where the current perpendicular to plane is affected by the interfaces. Robust intrinsic PMA can be achieved in certain Co[Formula: see text]Pt[Formula: see text] alloys and compounds at any thickness, without increasing the number of interfaces. Here, we grow equiatomic Co[Formula: see text]Pt[Formula: see text] and report a comprehensive study on the structural, magnetic, and spin-polarisation properties in the [Formula: see text] and [Formula: see text] ordered compounds. Primarily, interest in Co[Formula: see text]Pt[Formula: see text] has been in the [Formula: see text] crystal structure, where layers of Pt and Co are stacked alternately in the [100] direction. There has been less work on [Formula: see text] crystal structure, where the stacking is in the [111] direction. For the latter [Formula: see text] crystal structure, we find magnetic anisotropy perpendicular to the film plane. For the former [Formula: see text] crystal structure, the magnetic anisotropy is perpendicular to the [100] plane, which is neither in-plane or out-of-plane in our samples. We obtain a value for the ballistic spin polarisation of the [Formula: see text] and [Formula: see text] Co[Formula: see text]Pt[Formula: see text] to be [Formula: see text].
具有垂直磁各向异性的铁磁薄膜在自旋电子学和超导自旋电子学领域备受关注。当通过精心设计的界面驱动各向异性时，在薄铁磁多层结构中可以实现垂直磁各向异性。对于我们在超导自旋电子学中的应用而言，具有多个界面的器件存在不利之处，因为垂直于平面的电流会受到界面的影响。在某些特定厚度的Co[公式：见原文]Pt[公式：见原文]合金和化合物中，可以实现强大的本征垂直磁各向异性，而无需增加界面数量。在此，我们生长了等原子比的Co[公式：见原文]Pt[公式：见原文]，并报告了对[公式：见原文]和[公式：见原文]有序化合物的结构、磁性和自旋极化特性的全面研究。主要而言，对Co[公式：见原文]Pt[公式：见原文]的研究兴趣一直集中在[公式：见原文]晶体结构上，其中Pt和Co层在[100]方向上交替堆叠。对于[公式：见原文]晶体结构（堆叠方向为[111]）的研究较少。对于后一种[公式：见原文]晶体结构，我们发现其磁各向异性垂直于薄膜平面。对于前一种[公式：见原文]晶体结构，磁各向异性垂直于[100]平面，在我们的样品中该平面既不在面内也不在面外。我们测得[公式：见原文]和[公式：见原文]Co[公式：见原文]Pt[公式：见原文]的弹道自旋极化值为[公式：见原文]。
