Fermi level spin polarization of polycrystalline thulium by point contact Andreev reflection spectroscopy
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2011Access:
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Stamenov, P, Coey, JMD, Fermi level spin polarization of polycrystalline thulium by point contact Andreev reflection spectroscopy, Journal of Applied Physics, 109, 2011, 07C713-Download Item:
Abstract:
The spin polarization near the Fermi level in bulk polycrystalline ferrimagnetic thulium is
investigated by means of point contact Andreev reflection (PCAR), in the temperature interval
(1.9?9.2 K). The highest polarization measured is
P
?
0.41(8), with barrier parameter
Z
?
0.39(8),
proximity region gap of
D
1
?
1.26(5) meV and an elevation of the electronic temperature of
D
T
e
?
3.3(8) K, for a lattice temperature of
T
?
2.20(5) K, and a contact conductance of
G
?
330(5)
G
0
. Both polarization and barrier power are found to be constant within the experimental
uncertainties in the entire accessible temperature interval and linearly independent, while the
proximity gap was found to obey the standard BCS temperature dependence with a
T
cGap
?
10.2(2) K,
higher than the
T
cGap
?
9.2 K of bulk niobium. Despite its low ordering temperature, thulium could
be suitable candidate for low critical current spin-transfer-torque demonstrations.
Sponsor
Grant Number
Science Foundation Ireland (SFI)
SPIN
European Union (EU)
Author's Homepage:
http://people.tcd.ie/jcoeyhttp://people.tcd.ie/stamenp
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Author: COEY, JOHN; STAMENOV, PLAMEN
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Journal of Applied Physics109
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PhysicsDOI:
http://dx.doi.org/10.1063/1.3554254Metadata
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