Optimization of L1{sub 0} FePt/Fe{sub 45}Co{sub 55} thin films for rare earth free permanent magnet applications

Journal Article · Sun Jun 14 00:00:00 EDT 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4922506· OSTI ID:22412916

Psycharis, V.; Niarchos, D. ^[1]; Reichel, L. ^[2]; Markou, A.; Panagiotopoulos, I. ^[3]; Damm, C.; Fähler, S. ^[2]; Khan, Imran; Hong, Jisang ^[4]

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1. INN, NCSR Demokritos, Athens 15310 (Greece)
2. IFW Dresden, P.O. Box 270116, 01171 Dresden (Germany)
3. Department of Materials Science and Engineering, University of Ioannina, Ioannina 45110 (Greece)
4. Department of Physics, Pukyong National University, Busan 608-737 (Korea, Republic of)

The magnetic properties of magnetron sputtered bilayers consisting of Fe{sub 45}Co{sub 55} ultrathin layers on top of L1{sub 0} FePt films epitaxially grown on MgO substrates are studied in view of their possible application as rare earth free permanent magnets. It is found that FePt layers induce a tetragonal distortion to the Fe-Co layers which leads to increased anisotropy. This allows to take advantage of the Fe-Co high magnetic moment with less significant loss of the coercivity compared to a typical hard/soft exchange spring system. A maximum energy product approaching 50 MGOe is obtained for a FePt(7 ML)/FeCo/(5 ML) sample. The results are in accordance with first-principles computational methods, which predict that even higher energy products are possible for micromagnetically optimized microstructures.

• OSTI ID: 22412916
• Journal Information: Journal of Applied Physics, Vol. 117, Issue 22; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANISOTROPY
COBALT
COERCIVE FORCE
COMPARATIVE EVALUATIONS
CRYSTAL GROWTH
EPITAXY
INTERMETALLIC COMPOUNDS
IRON
LAYERS
MAGNESIUM OXIDES
MAGNETIC MOMENTS
MAGNETIC PROPERTIES
MICROSTRUCTURE
OPTIMIZATION
PERMANENT MAGNETS
SPUTTERING
SUBSTRATES
THIN FILMS