TY - JOUR
T1 - Inter-particle spin-polarized tunneling in arrays of magnetite nanocrystals
AU - Taub, Nurit
AU - Tsukernik, Alexander
AU - Markovich, Gil
N1 - Funding Information:
This work was supported by the Israel Science foundation, Grant no 779/06, and by the James Frank program. N.T. acknowledges the support granted by the Levi Eshkol Foundation, the Ministry of Science Culture & Sport Israel. The authors gratefully acknowledge useful comments from I. Sternfeld, and technical assistance from M. Karpovsky, A. Palevsky. A careful reading of the manuscript by A. Gerber is gratefully appreciated.
PY - 2009/7
Y1 - 2009/7
N2 - Inter-particle spin-polarized tunneling was measured in an organically capped magnetite nanocrystal (NC) array deposited between 30 nm spaced gold electrodes. Magnetoresistance (MR) measurements performed around the blocking temperature (Tb) of the magnetic moments of the particles in the array, which was relatively high (220 K), yielded negative MR values of the order of 10-25% under moderate magnetic fields of several kOe. The field dependence of the MR followed closely the square of the film's magnetization and its voltage dependence indicated maximal spin polarization around the Fermi level. These findings suggested that the measured MR is the result of spin-polarized tunneling between individual magnetite NCs acting as superparamagnetic spin polarizers.
AB - Inter-particle spin-polarized tunneling was measured in an organically capped magnetite nanocrystal (NC) array deposited between 30 nm spaced gold electrodes. Magnetoresistance (MR) measurements performed around the blocking temperature (Tb) of the magnetic moments of the particles in the array, which was relatively high (220 K), yielded negative MR values of the order of 10-25% under moderate magnetic fields of several kOe. The field dependence of the MR followed closely the square of the film's magnetization and its voltage dependence indicated maximal spin polarization around the Fermi level. These findings suggested that the measured MR is the result of spin-polarized tunneling between individual magnetite NCs acting as superparamagnetic spin polarizers.
KW - Magnetite nanocrystals
KW - Spin-polarized transport
KW - Superparamagnetism
KW - Tunneling magnetoresistance
UR - http://www.scopus.com/inward/record.url?scp=64749109407&partnerID=8YFLogxK
U2 - 10.1016/j.jmmm.2008.12.012
DO - 10.1016/j.jmmm.2008.12.012
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AN - SCOPUS:64749109407
SN - 0304-8853
VL - 321
SP - 1933
EP - 1938
JO - Journal of Magnetism and Magnetic Materials
JF - Journal of Magnetism and Magnetic Materials
IS - 13
ER -