Low frequency noise characteristics of submicron magnetic tunnel junctions

Low-frequency magnetic and resistance noise in magnetic tunnel junctions

We have studied the voltage fluctuations of current-biased, micron-scale magnetic tunnel junctions. We find that the spectral power density is 1/f -like at low frequencies and becomes frequency independent at high frequencies. The frequency-independent background noise is due to Johnson-Nyquist noise and shot noise mechanisms. The nature of the 1/f noise has its origin in two different mechanis...

Low-frequency magnetic noise in micron-scale magnetic tunnel junctions.

We have observed low-frequency noise due to quasiequilibrium thermal magnetization fluctuations in micron-scale magnetic tunnel junctions (MTJs). This strongly field-dependent magnetic noise occurs within the magnetic hysteresis loops, either as 1/f or Lorentzian (random telegraph) noise. We attribute it to the thermally excited hopping of magnetic domain walls between pinning sites. Our result...

Low Voltage I-V Characteristics in Magnetic Tunnel Junctions

We show that elastic currents that take into account variations of the tunnel transmitivity with voltage and a large ratio of majority to minority spin densities of states of the s band, can account for the low voltage current anomalies observed in magnet-oxide-magnet junctions. The anomalies can be positive, negative or have a mixed form, depending of the position of the Fermi level in the s b...

Low frequency noise in Co/Al2O3[lang]Si[rang]/Py magnetic tunnel junctions

Low frequency noise in Co/Al2O3〈δ(Fe)〉/Ni80Fe20 magnetic tunnel junctions

Abstract The time dependences, up to 200 s, and the noise power spectrum (0.005–10 Hz) in the electron transport response at bias up to 300 mV of Co/Al2O3/Ni80Fe20 magnetic tunnel junctions (MTJs) and of Co/Al2O3〈δ(Fe)〉/Ni80Fe20 (with Fe δ dopants of thickness 1.8 Å inside the barrier) were investigated. The magnetic field was changed between +100 and −100 G in steps of 1 G. The measurements we...