LAUSR

A study of the resistive and low-temperature magnetoresistive properties of pressed powders of ferromagnetic half-metal chromium dioxide CrO2 with nanoparticle shape anisotropy. The effects of Fe impurities on the tunneling resistance and magnetoresistance of CrO2 powders are investigated. It is found that the Fe impurity leads to a decrease in the resistance and tunneling magnetoresistance of chromium dioxide. It is suggested that the decrease in magnetoresistance of the solid solution Cr1-xFexO2 is associated with the formation of additional localized states at the iron impurities in a tunnel barrier. The influence of the magnetic field input rate on the form of the low-temperature tunneling magnetoresistance hysteresis in Cr1-xFexO2 powder is considered. It is shown that the low-temperature singularities of magnetoresistance hysteresis depend on the relaxation rate of the magnetic moments of the nanoparticles to the equilibrium state. Possible reasons for such a dependence are discussed.