Combinatorial study of Fe-Co-V hard magnetic thin films

Sean W Fackler; Vasileios Alexandrakis; Dennis König; A Gilad Kusne; Tieren Gao; Matthew J Kramer; Drew Stasak; Kenny Lopez; Brad Zayac; Apurva Mehta; Alfred Ludwig; Ichiro Takeuchi

doi:10.1080/14686996.2017.1287520

Combinatorial study of Fe-Co-V hard magnetic thin films

Sci Technol Adv Mater. 2017 Mar 20;18(1):231-238. doi: 10.1080/14686996.2017.1287520. eCollection 2017.

Authors

Affiliations

¹ Department of Materials Science & Engineering, University of Maryland, College Park, MD, USA.
² Materials Measurement Science Division, Institute for Materials, Ruhr-Universität Bochum, Bochum, Germany.
³ National Institute of Standards and Technology, Gaithersburg, MD, USA.
⁴ Ames Laboratory and Materials Science and Engineering, Iowa State University, Ames, IA, USA.
⁵ Stanford Synchrotron Radiation Lightsource/SLAC, Stanford University, Menlo Park, CA, USA.

Abstract

Thin film libraries of Fe-Co-V were fabricated by combinatorial sputtering to study magnetic and structural properties over wide ranges of composition and thickness by high-throughput methods: synchrotron X-ray diffraction, magnetometry, composition, and thickness were measured across the Fe-Co-V libraries. In-plane magnetic hysteresis loops were shown to have a coercive field of 23.9 kA m^-1 (300 G) and magnetization of 1000 kA m^-1. The out-of-plane direction revealed enhanced coercive fields of 207 kA m^-1 (2.6 kG) which was attributed to the shape anisotropy of column grains observed with electron microscopy. Angular dependence of the switching field showed that the magnetization reversal mechanism is governed by 180° domain wall pinning. In the thickness-dependent combinatorial study, co-sputtered composition spreads had a thickness ranging from 50 to 500 nm and (Fe₇₀Co₃₀)_100-xV_x compositions of x = 2-80. Comparison of high-throughput magneto-optical Kerr effect and traditional vibrating sample magnetometer measurements show agreement of trends in coercive fields across large composition and thickness regions.

Keywords: 203 Magnetics / Spintronics / Superconductors; 306 Thin film / Coatings; 50 Energy Materials; Vicalloy; combinatorial thin film; high-throughput; permanent magnet.