A magnetic tunneling junction (MTJ) with a structure of SiO2 20 nm/Ta 5 nm/Cu 20 nm/Ta 5 nm/NiFe 2 nm/Cu 5 nm/MnIr 10 nm/CoFe 4 nm/Al–O 1.5 nm/CoFe 4 nm/NiFe 20 nm/Ta 50 nm was measured by conducting atomic force microscopy (CAFM) to obtain I–V curves. The magnetoresistance (MR) ratio valued was determined from these I–V curves. Switching field of the free layer was obtained from hysteresis loop analysis derived by alternating gradient magnetometer (AGM). The MR ratio values were measured for several ramping DC bias voltage rates. We found that a low MR ratio was obtained with the highest ramping rate. Moreover, area-resistance (RA) value of MTJ device was also obtained.
Journal of Magnetism and Magnetic Materials, 304(1): e294-e296