Magnetoresistance enhanced by inelastic cotunneling in a ferromagnetic MnAs nanoparticle sandwiched by nonmagnetic electrodes Available to Purchase

We investigated electron transport and magnetoresistance (MR) of a nanoparticle system by measuring the vertical transport in heterostructures containing ferromagnetic MnAs nanoparticles and nonmagnetic electrodes. The origin of MR is attributed to the tunneling anisotropic MR (TAMR) of a MnAs nanoparticle because the path of electrons includes only a single ferromagnetic material, and MR shows magnetic-field direction dependence. From the very similar temperature dependence of the intensity of inelastic cotunneling and MR, it is strongly suggested that MR is enhanced by spin-dependent inelastic cotunneling. The temperature dependence of MR is explained by the magnetic energy barrier E_TAMR induced by TAMR, and E_TAMR is estimated to be ∼0.26 meV.