The mechanism,characteristics,primary applications,background,and latest research on the tunnelling magnetoresistance effects of magnetic tunnel junctions(MTJs) are reviewed.

The MTJs with tunneling magnetoresistance (TMR) ratio of 30%—48% can be directly obtained for the structure of Ta(5 nm)/Cu(25 nm)/Ni_ 79Fe_ 21(.

The typical values of junction resistance_area product and tunneling magnetoresistance (TMR) ratio of the MTJs are 16 kΩμm 2 and 18% respectively.

For example, the MTJs of Co/Al 2O 3/Co with a tunneling magnetoresistance (TMR) ratio of 17 2%, the junction resistance of .

Based on the twoband model,we investigate the tunnel magnetoresistance(TMR) in ferromagentic tunnel junction covered on both sides by nonmagnetic metal layers subjected to an electric field.

The influence of thickness of insulator layer and magnetic semiconductor layer on the tunnel magnetoresistance(TMR) and conductance are studied for different Rashba spin-orbit coupling strength and the different angle θ between the two magnetic moments of the left and right magnetic semiconductor layer.

In this article,a survey of the applications for giant-magnetoresistance(GMR) and tunneling magnetoresistance(TMR) as well as spin transfer is presented with the emphasis on the operative physical properties of the spintronic devices,including magnetic field sensors,galvanic isolators,read heads,random access memories,spin transfer switches and spin torque nano-oscillators.

By using the coherent quantum transport theory and transfer matrix method,the transmission coefficient and tunnel magnetic resistance for polarized electrons with different spin orientations through ferromagnetic/semiconductor/ferromagnetic tunnel junctions are investigated.