title: Direct magnetic patterning due to the generation of ferromagnetism by selective ion irradiation of paramagnetic FeAl alloys.
abstract: Sub-100-nm magnetic dots embedded in a non-magnetic matrix are controllably generated by selective ion irradiation of paramagnetic Fe(60)Al(40) (atomic %) alloys, taking advantage of the disorder-induced magnetism in this material. The process is demonstrated by sequential focused ion beam irradiation and by in-parallel broad-beam ion irradiation through lithographed masks. Due to the low fluences used, this method results in practically no alteration of the surface roughness. The dots exhibit a range of magnetic properties depending on the size and shape of the structures, with the smallest dots (<100 nm) having square hysteresis loops with coercivities in excess of micro(0)H(C) = 50 mT. Importantly, the patterning can be fully removed by annealing. The combination of properties induced by the direct magnetic patterning is appealing for a wide range of applications, such as patterned media, magnetic separators, or sensors.
authors.affiliation: Departament de Física, Universitat Autònoma de Barcelona, Bellaterra, Spain.
authors.forename: Enric
authors.initials: E
authors.lastname: Menéndez
authors.forename: Maciej Oskar
authors.initials: MO
authors.lastname: Liedke
authors.forename: Jürgen
authors.initials: J
authors.lastname: Fassbender
authors.forename: Thomas
authors.initials: T
authors.lastname: Gemming
authors.forename: Anja
authors.initials: A
authors.lastname: Weber
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Heyderman
authors.forename: K V
authors.initials: KV
authors.lastname: Rao
authors.forename: Seetharama C
authors.initials: SC
authors.lastname: Deevi
authors.forename: Santiago
authors.initials: S
authors.lastname: Suriñach
authors.forename: Maria Dolors
authors.initials: MD
authors.lastname: Baró
authors.forename: Jordi
authors.initials: J
authors.lastname: Sort
authors.forename: Josep
authors.initials: J
authors.lastname: Nogués
mesh_terms: D000497:Alloys; D000535:Aluminum / Q000737:chemistry*; D015374:Biosensing Techniques; D004867:Equipment Design; D007477:Ions; D007501:Iron / Q000737:chemistry*; D008280:Magnetics; D008670:Metals; D018625:Microscopy, Atomic Force / Q000295:instrumentation / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D011108:Polymers / Q000737:chemistry; D013499:Surface Properties
chemical_list: D000497:Alloys; D007477:Ions; D008670:Metals; D011108:Polymers; D000535:Aluminum; D007501:Iron