Abstract
| Original language | Undefined |
|---|---|
| Pages (from-to) | 4933-4940 |
| Number of pages | 8 |
| Journal | Advanced functional materials |
| Volume | 23 |
| Issue number | 39 |
| DOIs | |
| Publication status | Published - 15 Apr 2013 |
Keywords
- solid phase epitaxy
- EWI-24391
- Amorphous ferromagnetic alloys
- IR-89177
- Spintronics
- graphite
- METIS-298196
- Interfaces
Cite this
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Crystalline CoFeB/graphite interfaces for carbon spintronics fabricated by solid phase epitaxy. / Wong, P.K.J.; van Geijn, Elmer; van Geijn, E.; Zhang, W.; Starikov, A.A.; Tran, T. Lan Ahn; Sanderink, Johannes G.M.; Siekman, Martin Herman; Brocks, Gerardus H.L.A.; Kelly, Paul J.; van der Wiel, Wilfred Gerard; de Jong, Machiel Pieter.
In: Advanced functional materials, Vol. 23, No. 39, 15.04.2013, p. 4933-4940.Research output: Contribution to journal › Article › Academic › peer-review
TY - JOUR
T1 - Crystalline CoFeB/graphite interfaces for carbon spintronics fabricated by solid phase epitaxy
AU - Wong, P.K.J.
AU - van Geijn, Elmer
AU - van Geijn, E.
AU - Zhang, W.
AU - Starikov, A.A.
AU - Tran, T. Lan Ahn
AU - Sanderink, Johannes G.M.
AU - Siekman, Martin Herman
AU - Brocks, Gerardus H.L.A.
AU - Kelly, Paul J.
AU - van der Wiel, Wilfred Gerard
AU - de Jong, Machiel Pieter
PY - 2013/4/15
Y1 - 2013/4/15
N2 - Structurally ordered interfaces between ferromagnetic electrodes and graphene or graphite are of great interest for carbon spintronics, since they allow spin-filtering due to k-vector conservation. By solid phase epitaxy of amorphous/nanocrystalline CoFeB at elevated temperatures, the feasibility of fabricating crystalline interfaces between a 3d ferromagnetic alloy and graphite is demonstrated, without suffering from the unwetting problem that was commonly seen in many previous studies with 3d transition metals. The films fabricated on graphite in this way are found to have a strong body-centered-cubic (110) texture, albeit without a unique, well-defined in-plane epitaxial relationship with the substrate lattice. Using various X-ray spectroscopic techniques, it is shown that boron suppresses the formation of CoFe-O during CoFeB deposition, and then diffuses out of the CoFe lattice. Segregation of B occurred exclusively to the film surface upon in situ annealing, and not to the interface between CoFeB and graphite. This is favorable for obtaining a high spin polarization at the hybrid CoFe/graphite crystalline interface. The Co and Fe spin moments in the crystalline film, determined by X-ray magnetic circular dichroism, are found to be bulk-like, while their orbital moments show an unusual giant enhancement which has yet to be understood.
AB - Structurally ordered interfaces between ferromagnetic electrodes and graphene or graphite are of great interest for carbon spintronics, since they allow spin-filtering due to k-vector conservation. By solid phase epitaxy of amorphous/nanocrystalline CoFeB at elevated temperatures, the feasibility of fabricating crystalline interfaces between a 3d ferromagnetic alloy and graphite is demonstrated, without suffering from the unwetting problem that was commonly seen in many previous studies with 3d transition metals. The films fabricated on graphite in this way are found to have a strong body-centered-cubic (110) texture, albeit without a unique, well-defined in-plane epitaxial relationship with the substrate lattice. Using various X-ray spectroscopic techniques, it is shown that boron suppresses the formation of CoFe-O during CoFeB deposition, and then diffuses out of the CoFe lattice. Segregation of B occurred exclusively to the film surface upon in situ annealing, and not to the interface between CoFeB and graphite. This is favorable for obtaining a high spin polarization at the hybrid CoFe/graphite crystalline interface. The Co and Fe spin moments in the crystalline film, determined by X-ray magnetic circular dichroism, are found to be bulk-like, while their orbital moments show an unusual giant enhancement which has yet to be understood.
KW - solid phase epitaxy
KW - EWI-24391
KW - Amorphous ferromagnetic alloys
KW - IR-89177
KW - Spintronics
KW - graphite
KW - METIS-298196
KW - Interfaces
U2 - 10.1002/adfm.201203460
DO - 10.1002/adfm.201203460
M3 - Article
VL - 23
SP - 4933
EP - 4940
JO - Advanced functional materials
JF - Advanced functional materials
SN - 1616-301X
IS - 39
ER -