Systematic tuning of segmented magnetic nanowires into three-dimensional arrays of 'bits'. Issue 60 (31st July 2017)

• Record Type: Journal Article
• Authors: Bochmann, S.; Fernandez-Pacheco, A.; Mačković, M.; Neff, A.; Siefermann, K. R.; Spiecker, E.; Cowburn, R. P.; Bachmann, J.
• Is Part Of: RSC advances. Volume 7:Issue 60(2017)
• Page Start: 37627
• Page End: 37635
• Publication Date: 2017-07-31
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c7ra06734h
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : A method is presented for the preparation of a three-dimensional magnetic data storage material system. Abstract : A method is presented for the preparation of a three-dimensional magnetic data storage material system. The major ingredients are an inert nanoporous matrix prepared by anodization and galvanic plating of magnetic and non-magnetic metals in wire shape inside the cylindrical pores. The individual nanomagnets consist of a nickel–cobalt alloy, the composition of which is tuned systematically by adjusting the electrolytic bath composition at one optimal applied potential. The lowest magnetocrystalline anisotropy is obtained at the composition Ni60 Co40, as quantified by superconducting quantum interference device magnetometry. Wires of this composition experience a pinning-free propagation of magnetic domain walls, as determined by single-wire magneto-optical Kerr effect magnetometry. Adding copper into the electrolyte allows one to generate segments of Ni60 Co40 separated by non-magnetic copper. The segment structure is apparent in individual nanowires imaged by scanning electron microscopy, UV-photoelectron emission microscopy, and transmission electron microscopy. The single-domain structure of the wire segments is evidenced by magnetic force microscopy.