Magnetotransport properties and kondo effect observed in a ferromagnetic single-crystalline Fe(1-x)Co(x)Si nanowire.

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.

[1]  Liang Li,et al.  ZnS nanostructures: From synthesis to applications , 2011 .

[2]  S. Kokado,et al.  Negative Anisotropic Magnetoresistance in Fe4N Film , 2009 .

[3]  Takashi Sekiguchi,et al.  Single‐Crystalline ZnS Nanobelts as Ultraviolet‐Light Sensors , 2009 .

[4]  H. Takagi,et al.  Marginal breakdown of the Fermi-liquid state on the border of metallic ferromagnetism , 2008, Nature.

[5]  Jeunghee Park,et al.  Quantum interference in radial heterostructure nanowires. , 2008, Nano letters (Print).

[6]  T. Rosenbaum,et al.  Classical and quantum routes to linear magnetoresistance. , 2008, Nature materials.

[7]  Kwanyong Seo,et al.  Single-Crystalline Ferromagnetic Fe1-xCoxSi Nanowires , 2008 .

[8]  I. Affleck,et al.  Friedel oscillations and the Kondo screening cloud , 2008, 0802.0280.

[9]  Song Jin,et al.  Chemical synthesis and magnetotransport of magnetic semiconducting Fe1-xCoxSi alloy nanowires. , 2008, Nano letters.

[10]  M. S. Figueira,et al.  Low temperature properties of the Kondo insulator FeSi , 2007 .

[11]  Y. Tokura,et al.  Real-Space Observation of Helical Spin Order , 2006, Science.

[12]  H. Takagi,et al.  Doping dependence of transport properties in Fe 1 − x Co x Si , 2005 .

[13]  J. Guevara,et al.  Half-metallic character and electronic properties of inverse magnetoresistantFe1−xCoxSialloys , 2004 .

[14]  E. A. Payzant,et al.  Synthesis of ternary nitrides from intermetallic precursors: Modes of nitridation in model Cr3Pt alloys to form Cr3PtN antiperovskite and application to other systems , 2004 .

[15]  M. Ferretti,et al.  Application of the SHS technique in the synthesis of the perovskite-type MgxCyNi3 compound , 2004 .

[16]  Gabriel Aeppli,et al.  Large anomalous Hall effect in a silicon-based magnetic semiconductor , 2004, Nature materials.

[17]  Y. Yeshurun,et al.  Fabrication of the MgCxCo3 Ternary Phase Encapsulated in Carbon Nanoflasks , 2003 .

[18]  S. Chaudhary,et al.  Magnetic response ofFe1−xCoxSialloys: A detailed study of magnetization and magnetoresistance , 2002 .

[19]  J. Guevara,et al.  Electronic and magnetic properties of the inverse magnetoresistant Fe1-xCoxsi alloys , 2002 .

[20]  M. Jung,et al.  Hall effect and magnetoresistance of YbAl3 , 2002 .

[21]  J. Thompson,et al.  Two energy scales and slow crossover in YbAl3. , 2001, Physical review letters.

[22]  Qi Li,et al.  Anomalous anisotropic magnetoresistance in Pr0.67Sr0.33MnO3 thin films , 2000 .

[23]  David P. Young,et al.  Magnetoresistance from quantum interference effects in ferromagnets , 2000, Nature.

[24]  Georges,et al.  Coherence scale of the kondo lattice , 2000, Physical review letters.

[25]  A. Abrikosov,et al.  Quantum linear magnetoresistance , 2000 .

[26]  S. Parkin,et al.  Negative Domain Wall Contribution to the Resistivity of Microfabricated Fe Wires , 1998, cond-mat/9803102.

[27]  A. Damascelli,et al.  Spin, charge, and bonding in transition metal mono-silicides , 1997, cond-mat/9709018.

[28]  Z. Fisk,et al.  Low-temperature transport, optical, magnetic and thermodynamic properties of Fe 1-x Co x Si , 1997 .

[29]  Z. Fisk,et al.  Low-temperature magnetic and thermodynamic properties of Fe1 − xCoxSi , 1997 .

[30]  Fu,et al.  Electronic structure and optical properties of FeSi, a strongly correlated insulator. , 1994, Physical review. B, Condensed matter.

[31]  Giordano,et al.  Kondo effect in one-dimensional Au(Fe). , 1992, Physical Review B (Condensed Matter).

[32]  Park,et al.  Finite-size effects in the low-temperature resistivity of CuCr films. , 1992, Physical Review Letters.

[33]  T. Mcguire,et al.  Negative anisotropic magnetoresistance in 3d metals and alloys containing iridium , 1984 .

[34]  M. Roth,et al.  Long period helimagnetism in the cubic B20 FexCo1−xSi and CoxMn1−x Si alloys , 1983 .

[35]  T. Mcguire,et al.  Anisotropic magnetoresistance in ferromagnetic 3d alloys , 1975 .

[36]  R. Sherwood,et al.  Magnetic behavior of the monosilicides of the 3d-transition elements , 1972 .

[37]  A. Fert,et al.  The spontaneous resistivity anisotropy in Ni-based alloys , 1970 .

[38]  Albert Fert,et al.  Two-Current Conduction in Nickel , 1968 .

[39]  L. Walker,et al.  Paramagnetic Excited State of FeSi , 1967 .

[40]  S. Kauzlarich,et al.  Magnetism and colossal magnetoresistance of the pseudo-ternary rare-earth transition-metal compounds, Eu14-xCaxMnSb11 (x < 3) , 2002 .