Related papers: Backhopping effect in magnetic tunnel junctions: c…
We analyse the phenomenon of back-hopping in spin-torque induced switching of the magnetization in perpendicularly magnetized tunnel junctions. The analysis is based on single-shot time-resolved conductance measurements of the pulse-induced…
We report on room temperature magnetoresistance and low frequency noise in sub-100nm elliptic CoFeB/MgO/CoFeB magnetic tunnel junctions with ultrathin (0.9nm) barriers. For magnetic fields applied along the hard axis, we observe current…
Magnetic tunnel junctions for spin-transfer torque switching were prepared to investigate the dielectric breakdown. The breakdown occurs typically at voltages not much higher than the switching voltages, a bottleneck for the implementation…
We present spin transfer switching results for MgO based magnetic tunneling junctions (MTJs)with large tunneling magnetoresistance (TMR) ratio of up to 150% and low intrinsic switching current density of 2-3 x 10 MA/cm2. The switching data…
This chapter presents a review on spin transfer torque in magnetic tunnel junctions. In the first part, we propose an overview of experimental and theoretical studies addressing current-induced magnetization excitations in magnetic tunnel…
We study ns scale spin-torque-induced switching in perpendicularly magnetized tunnel junctions (pMTJ). Although the switching voltages match with the macrospin instability threshold, the electrical signatures of the reversal indicate the…
A new mechanism different from the spin accumulation picture is proposed for the current induced magnetization switching in magnetic tunnel junctions by taking into account the effect of the electron electron interaction. We found in tunnel…
We examine the spin torque (ST) response of magnetic tunnel junctions (MTJs) with ultra-thin MgO tunnel barrier layers to investigate the relationship between the spin-transfer torque and the tunnel magnetoresistance (TMR) under finite…
The dependence of tunneling magnetoresistance and spin-transfer torque in FeCo/MgO/FeCo tunnel junctions on the Co concentration and the bias voltage are investigated ab initio. We find that the tunneling magnetoresistance decreases with…
Perpendicular magnetic tunnel junctions based on MgO/CoFeB structures are of particular interest for magnetic random-access memories because of their excellent thermal stability, scaling potential, and power dissipation. However, the major…
Ultra-thin magnetic tunnel junctions with low resistive MgO tunnel barriers are prepared to examine their stability under large current stress. The devices show magnetoresistance ratios of up to 110 % and an area resistance product of down…
The resistive switching phenomenon in MgO-based tunnel junctions is attributed to the effect of charged defects inside the barrier. The presence of electron traps in the MgO barrier, that can be filled and emptied, locally modifies the…
We propose the use of resonant tunneling as a route to enhance the spin-transfer torque switching characteristics of magnetic tunnel junctions. The proposed device structure is a resonant tunneling magnetic tunnel junction based on a…
We report the observation and micromagnetic analysis of current-driven magnetization switching in nanoscale ring-shaped magnetic tunnel junctions. When the electric current density exceeds a critical value of the order of $6\times…
Here, we present an analytical and numerical model describing the magnetization dynamics in MgO-based spin-torque nano-oscillators with an in-plane magnetized polarizer and an out-of-plane free layer. We introduce the spin-transfer torque…
We report measurements of magnetic switching and steady-state magnetic precession driven by spin-polarized currents in nanoscale magnetic tunnel junctions with low-resistance, < 5 Ohm-micron-squared, barriers. The current densities required…
We study the bias-dependent spin-transfer torque in magnetic tunnel junctions in the Stoner model by scattering theory. We show that the in-plane (Slonczewski type) torque vanishes and subsequently reverses its direction when the bias…
The spin-transfer effect has been studied in magnetic tunnel junctions (PtMn/CoFe/Ru/CoFe/Al2O3/CoFe/NiFe) with dimensions down to 0.1x0.2 um2 and resistance-area product RA in the range of 0.5-10 Ohm m2 (dR/R=1-20%). Current-induced…
This paper describes a numerical experiment of magnetization switching driven by spin-polarized current in high-TMR magnetic tunnel junctions (TMR>100%). Differently from other works, the current density distribution throughout the…
The influence of insertion of an ultra-thin NiO layer between the MgO barrier and ferromagnetic electrode in magnetic tunnel junctions has been investigated by measuring the tunneling magnetoresistance and the X-ray magnetic circular…