Direct magnetic patterning due to the generation of ferromagnetism by selective ion irradiation of paramagnetic FeAl alloys.
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.
Menéndez
Enric
E
Departament de Física, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Liedke
Maciej Oskar
MO
Fassbender
Jürgen
J
Gemming
Thomas
T
Weber
Anja
A
Heyderman
Laura J
LJ
Rao
K V
KV
Deevi
Seetharama C
SC
Suriñach
Santiago
S
Baró
Maria Dolors
MD
Sort
Jordi
J
Nogués
Josep
J
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
D000497:Alloys; D007477:Ions; D008670:Metals; D011108:Polymers; D000535:Aluminum; D007501:Iron