Unidirectional spin Hall magnetoresistance in epitaxial Cr/Fe bilayer from electron-magnon scattering

Unidirectional Spin Hall magnetoresistance (USMR) is a non-linear phenomenon recently observed in ferromagnet (FM)/nonmagnetic metal (NM) bilayer structures. Two very different mechanisms of USMR have been proposed; one relies on the current-direction-dependence of electron-magnon scattering in a FM layer, and the other on the current-direction-dependence of the spin accumulation at the FM/NM interface. In this study, we investigate the USMR in epitaxial Cr/Fe bilayers finding that the USMR is significantly enhanced when the Fe magnetization is aligned to a particular crystallographic direction where the magnon magnetoresistance (MMR) by the electron-magnon scattering becomes stronger. This highlights the importance of the electron-magnon scattering for the understanding of USMR in Cr/Fe bilayers. Our result also suggests a route to enhance the efficiency of magnon generation in the magnonic devices. Lastly, we discuss the Ising-type spin exchange as a possible origin of the crystallographic direction dependences of the USMR and the MMR.

Огромное магнетосопротивление в структуре металл--органический полупроводник--металл

The article represents results of huge magnetoresistance effect investigation in the structure of magnetic metal / organic semiconductor / nonmagnetic metal with magnitude of ~ 2600%. There are observed influence of magnetic field on concentration and mobility of charge carriers and on magnitude of ferromagnetic/semiconductor potential barrier. Theoretical interpretation is considered with previously discussed model. The model describes influence of hyperfine fields on spin selective hopping rate between the sites in the polymer

Study of hysteresis effects in spin-valve sandwich structure.

The Monte Carlo simulation of magnetic properties of spin-valve sandwich structures, where ultrathin ferromagnetic films divided by layer of nonmagnetic metal, and antiferromagnetic, are coupled antiferromagnetically, is realized. The anisotropic Heisenberg model is applied for description of magnetic properties. Dependence of hysteresis phenomena on thickness of ferromagnetic films and various values of interlayer exchange interaction is revealed.

Structural and Electronic Properties of B-Doped ZnO Monolayer

The geometrical and electronic properties of B-doped ZnO monolayer with the concentrations of 12.5% and 25% have been calculated using the first-principles method. B-doped ZnO monolayer leads to the structural distortion around the doped atoms compared with the pure ZnO sheet. The B-B pair or two B-B pairs doped ZnO monolayer present nonmagnetic metal.

SIMULATION OF HYSTERESIS PHENOMENA IN MULTILAYER MAGNETIC NANOSTRUCTURES

The Monte Carlo simulation of magnetic properties of artificial multilayer nanostructures, where ultrathin ferromagnetic films divided by layer of nonmagnetic metal are coupled antiferromagnetically, is realized. The anisotropic Heisenberg model is applied for de-scription of magnetic properties. Dependence of hysteresis phenomena on thickness of ferromagnetic films and various values of interlayer exchange interaction is revealed.