Complex magnetic response in magnetic tunnel junctions determined via magnetic and transport measurements

摘要

We have studied the low frequency complex magnetization dynamics in Co/Al_2O_3/Ni_(80)Fe_(20) magnetic tunnel junctions (MTJs) at temperatures between 4.2K and 300K. The measurements were carried out by using two different experimental techniques. The first method probes directly magnetic properties via DC magnetization and AC susceptibility, while the second one measures AC magnetization dynamics of the ferromagnetic electrodes near the cross area, which is related to the tunnelling resistance.