We propose a general formalism to describe accurately the angular dependence of the magnetoresistance. A parabolic band model is used to determine without approximation the conductance of arbitrary complex heterostructures. Simple analytical expressions are obtained in some limit cases. Particularly, we show that significant deviation from the cosine dependence is expected for ferromagnetic bar...

We present small-angle neutron scattering data proving that, on the insulating side of the metal-insulator transition, the doped perovskite cobaltite La(1-x)Sr(x)CoO(3) phase separates into ferromagnetic metallic clusters embedded in a nonferromagnetic matrix. This induces a hysteretic magnetoresistance, with temperature and field dependence characteristic of intergranular giant magnetoresistan...

The magnetoresistance sMRd studies of magnetite thin films deposited on vicinal MgO substrates show an enhanced MR along the miscut direction as compared to the direction perpendicular to it. The MR anisotropy increases with the decrease in temperature and peaks at the Verwey transition. The increase in magnetoresistance and anisotropy behavior is attributed to the formation of a greater number...

Ni/Co multilayers grown by molecular beam epitaxy are found to exhibit a magnetoresistance AR/R at liquid helium temperature as large as 8.2%, with saturation fields AH-22 Oe and a sensitivity (AR/R)/(2AH)=O. 19% Oe-‘. The highest room temperature sensitivity obtained to date in this system is 0.18% Oe-’ and at 4.2 K is 0.29% Oe-‘. This demonstrates that high values of the sensitivity can be ac...

We study transport in ferromagnetic single-electron transistors. The non-equilibrium spin accumulation on the island caused by a finite current through the system is described by a generalized theory of the Coulomb blockade. It enhances the tunnel magnetoresistance and has a drastic effect on the time-dependent transport properties. A transient decay of the spin accumulation may reverse the ele...

Phonon-assisted electronic tunneling is studied through a double quantum dot coupled in parallel to ferromagnetic electrodes. The current voltage characteristics for the system are derived within the nonequilibrium Green function technique based on equation of motion. It is found that additional phonon-induced resonance peaks appear in the spectral function on both sides of the main resonances ...

The magnetoresistance of Ni/V2O3/Py devices shows interesting behavior in the temperature dependence across the V2O3 metal-insulator transition. A spin-valve effect ( 0.1%) is found below the transition temperature when V2O3 is in the insulating phase. Contrary to expectation, the spin-valve effect disappears when device is heated above 150 K and V2O3 is in the metallic state. At these temperat...

ni-co/cu multilayers have been grown by electrodeposition method from a single electrolyte (based on ni(so4).6h2o, co(so4).7h2o, cu(so4) and h3bo3) using galvanostatic control on titanium sublayers. the x-ray diffraction (xrd) patterns confirmed the multilayered structure with the nanometer thicknesses. also, electron diffraction x-ray (edx)  analysis confirmed the purity of deposited samples. ...

Magnetic field effects on single-particle energy bands (Hofstadter butterfly), Hall conductance, flat-band ferromagnetism, and magnetoresistance of twodimensional Kagome lattices are studied. The flat-band ferromagnetism is shown to be broken as the flat-band has finite dispersion in the magnetic field. A metal-insulator transition induced by the magnetic field (giant negative magnetoresistance...