Co2FeSn Heusler Nanowires with High Spin Polarization

Abstract

Spin transfer electronics or spintronics offers the possibility of enhancement of regular electronic devices [1]. Because of that, the demand for materials that acquire high values of spin polarization is growing. From several groups of materials, half-metallic Co2-based Heusler alloys are well appropriate materials for spintronic devices due to their high Curie temperature, high magnetic moment, and low Gilbert dumping [2]. The majority of Heusler alloys are usually prepared in the form of ribbons, bulk, or thin films. However, due to technological progress, Heusler alloys face a new production challenge in the nano-scale regime. Several publications deal with the preparation of Heusler nanowires, but with the lack of the spin polarization measurements [3]. Magnetic nanowires prepared in the form of dense array offer the possibility for the development of next-level 3D magnetic “racetrack” memory. Here, the information is stored in the domain wall pattern and shift with spin-polarized current [4]. Therefore, it is essential to determine the spin polarization of the material, which is considered for possible spintronic applications. In the present work, Co2FeSn nanowires have been prepared using template-assisted electrochemical deposition. The nanowires have been grown in the pores of Anodic Alumna Oxide membranes. The spin polarization values have been determined using Point-Contact Andreev Reflection spectroscopy. We show that the spin polarization is preserved in the nanoscale, and by creating a contact with the fresh surface, it is possible to achieve high spin polarization values up to 100 %. This research was supported by Slovak Grant Agency VEGA 1/0053/19, Slovak Grant Agency grant number APVV-16-0079 and VVGS-2019-1231.