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Magnetotransport Properties and Kondo Effect Observed in a Ferromagnetic Single‐Crystalline Fe 1− x Co x Si Nanowire
Author(s) -
Lee Sunghun,
In Juneho,
Chang JungWon,
Seo Kwanyong,
Jung MyungHwa,
Kim Jinhee,
Kim Bongsoo
Publication year - 2012
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.201100679
Subject(s) - condensed matter physics , magnetoresistance , nanowire , ferromagnetism , materials science , electrical resistivity and conductivity , kondo effect , curie temperature , magnetization , anisotropy , atmospheric temperature range , magnetic field , physics , nanotechnology , quantum mechanics , meteorology
We report unconventional magnetotransport properties of an individual Fe 1− x Co x Si nanowire. We have studied the dependence of the resistivity on the angle between the directions of the magnetization and electrical current below the Curie temperature ( T C ). The observed anisotropic magnetoresistance (MR) ratio is negative, thereby indicating that the conduction electrons in a minority spin band of the Fe 1− x Co x Si nanowire dominantly contribute to the transport. Unlike typical ferromagnets, positive MR is observed in the overall temperature range. MR curves are linear below T C and show a quadratic form above T C , which can be explained by the change of density of states that arises as the band structures of the Fe 1− x Co x Si nanowire shift under a magnetic field. The temperature dependence of the resistivity curve is sufficiently explained by the Kondo effect. The Kondo temperature of the Fe 1− x Co x Si nanowire is lower than that of the bulk state due to suppression of the Kondo effect. The high single crystallinity of Fe 1− x Co x Si nanowires allowed us to observe and interpret quite subtle variations in the prominent intrinsic transport properties.