Long-term thermal stability is crucial for magnetic nanoparticles in ultrahigh density magnetic recording. For ledge-type exchange-spring nanocomposites consisting of a hard magnetic L10-FePt part and a soft magnetic Fe part of more extended horizontal size, the minimum energy barriers for thermal reversal between equilibrium states of the hysteresis loops are determined using a nudged-elastic-band path approach. The field dependence of the energy barrier can be described approximately by power laws. It turns out that nanopatterns of isolated ledge-type L10-FePt/Fe composite elements or isolated L10-FePt nanodots covered by a thin Fe film are well-suited in realizing ultrahigh recording densities.

Topics
Exchange interactions, Magnetic devices, Magnetic hysteresis, Magnetic materials, Materials properties, Thin films, Nanocomposites, Nanodots, Nanoparticle, Fungi
1.
R. H.
 
Victora
 and
X.
 
Shen
,
IEEE Trans. Magn.
https://doi.org/10.1109/TMAG.2004.838075
 
41
,
537
(
2005
).
Google Scholar
Crossref
Search ADS
 
2.
A. Y.
 
Dobin
 and
H. J.
 
Richter
,
Appl. Phys. Lett.
https://doi.org/10.1063/1.2335590
 
89
,
062512
(
2006
).
Google Scholar
Crossref
Search ADS
 
3.
A.
 
Goncharov
,
T.
 
Schrefl
,
G.
 
Hrkac
,
J.
 
Dean
,
S.
 
Bance
,
D.
 
Suess
,
O.
 
Ertl
,
F.
 
Dorfbauer
, and
J.
 
Fidler
,
Appl. Phys. Lett.
https://doi.org/10.1063/1.2804609
 
91
,
222502
(
2007
).
Google Scholar
Crossref
Search ADS
 
4.
M.
 
Ghidini
,
G.
 
Asti
,
R.
 
Pellicelli
,
C.
 
Pernechele
, and
M.
 
Solzi
,
J. Magn. Magn. Mater.
https://doi.org/10.1016/j.jmmm.2007.02.040
 
316
,
159
(
2007
).
Google Scholar
Crossref
Search ADS
 
5.
D.
 
Goll
 and
H.
 
Kronmüller
,
Physica B (Amsterdam)
 
403
,
1854
(
2008
).
Google Scholar
Crossref
Search ADS
 
6.
D.
 
Suess
,
J. Magn. Magn. Mater.
https://doi.org/10.1016/j.jmmm.2006.05.021
 
308
,
183
(
2007
).
Google Scholar
Crossref
Search ADS
 
7.
B.
 
Livshitz
,
A.
 
Inomata
,
H. N.
 
Bertram
, and
V.
 
Lomakin
,
Appl. Phys. Lett.
https://doi.org/10.1063/1.2801362
 
91
,
182502
(
2007
).
Google Scholar
Crossref
Search ADS
 
8.
D.
 
Goll
,
S.
 
Macke
, and
H. N.
 
Bertram
,
Appl. Phys. Lett.
https://doi.org/10.1063/1.2731519
 
90
,
172506
(
2007
).
Google Scholar
Crossref
Search ADS
 
9.
V.
 
Lomakin
,
R.
 
Choi
,
B.
 
Livshitz
,
S.
 
Li
,
A.
 
Inomata
, and
H. N.
 
Bertram
,
Appl. Phys. Lett.
https://doi.org/10.1063/1.2831732
 
92
,
022502
(
2008
).
Google Scholar
Crossref
Search ADS
 
10.
V.
 
Lomakin
,
B.
 
Livshitz
,
S.
 
Li
,
A.
 
Inomata
,
R.
 
Choi
, and
H. N.
 
Bertram
,
Abstract DA-03, Intermag 2008
,
Madrid
,
2008
(unpublished), p.
544
.
11.
D.
 
Goll
,
A.
 
Breitling
, and
S.
 
Macke
, “
Magnetic properties of exchange coupled L10-FePt/Fe composite elements
,”
IEEE Trans. Magn.
(in press).
12.
F.
 
Casoli
,
F.
 
Albertini
,
L.
 
Nasi
,
S.
 
Fabbrici
,
R.
 
Cabassi
,
F.
 
Bolzoni
, and
C.
 
Bocchi
,
Appl. Phys. Lett.
https://doi.org/10.1063/1.2905294
 
92
,
142506
(
2008
).
Google Scholar
Crossref
Search ADS
 
13.
H. N.
 
Bertram
 and
B.
 
Lengsfield
,
IEEE Trans. Magn.
https://doi.org/10.1109/TMAG.2007.892852
 
43
,
2145
(
2007
).
Google Scholar
Crossref
Search ADS
 
© 2008 American Institute of Physics.
2008
American Institute of Physics
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