Temperature dependence of tunnel magnetoresistance (TMR) ratio. resistance, and coercivity from 4.2 K to room temperature (RT), applied dc bias voltage dependence of the TMR ratio and resistances at 4.2 K and RT. tunn...Temperature dependence of tunnel magnetoresistance (TMR) ratio. resistance, and coercivity from 4.2 K to room temperature (RT), applied dc bias voltage dependence of the TMR ratio and resistances at 4.2 K and RT. tunnel current I and dynamic conductance dI/dV as functions of the dc bias voltage at 4.2 K, and inelastic electron tunneling (IET) spectroscopy, d2I/dV2 versus V, at 4.2 K for a tunnel junction of Ta(5 nm)/Ni79 Fe21 (25 nm)/lr22 Mn78(12 nm)/Co75 Fe25(4 nm)/ Al(0.8 um)-oxide/Co75Fe25(4 nm)/Ni79Fe21(25 nm)/Ta(5 um ) were systematically investigated High TMR ratio of 59.2% at 4.2 K and 41.3% at RT were observed for this junction after annealing at 275’C for an hour. The temperature dependence of TMR ratio and resistances from 4.2 to 300 K at 1.0 mV bias and the dc bias voltage dependence of TMR ratio at 4.2 K from 0 to 80 mV can be evaluated by a comparison of self-consistent calculations with the experimental data based on the magnon-assisted inelastic excitation model and theory. An anisotropic wavelength cutoff energy of spin-wave spectrum in magnetic tunnel junctions (MTJs) was suggested, which is necessary for self-consistent calculations, based on a series of IET spectra observed in the MTJs.展开更多
文摘Temperature dependence of tunnel magnetoresistance (TMR) ratio. resistance, and coercivity from 4.2 K to room temperature (RT), applied dc bias voltage dependence of the TMR ratio and resistances at 4.2 K and RT. tunnel current I and dynamic conductance dI/dV as functions of the dc bias voltage at 4.2 K, and inelastic electron tunneling (IET) spectroscopy, d2I/dV2 versus V, at 4.2 K for a tunnel junction of Ta(5 nm)/Ni79 Fe21 (25 nm)/lr22 Mn78(12 nm)/Co75 Fe25(4 nm)/ Al(0.8 um)-oxide/Co75Fe25(4 nm)/Ni79Fe21(25 nm)/Ta(5 um ) were systematically investigated High TMR ratio of 59.2% at 4.2 K and 41.3% at RT were observed for this junction after annealing at 275’C for an hour. The temperature dependence of TMR ratio and resistances from 4.2 to 300 K at 1.0 mV bias and the dc bias voltage dependence of TMR ratio at 4.2 K from 0 to 80 mV can be evaluated by a comparison of self-consistent calculations with the experimental data based on the magnon-assisted inelastic excitation model and theory. An anisotropic wavelength cutoff energy of spin-wave spectrum in magnetic tunnel junctions (MTJs) was suggested, which is necessary for self-consistent calculations, based on a series of IET spectra observed in the MTJs.
