We demonstrated the noise performances of Al 2O 3-based magnetic tunnel junction sensors (MTJs) in the low-frequency regimes. Conetic alloy Ni 77Fe 14 Cu 5Mo 4 was deposited as both the MTJ pinned layer and free layer because of its superb magnetically soft properties. A rotating magnetic field was employed to investigate the angular dependence of the MTJ low-frequency noise. Hooge parameter was applied for parameterizing the low-frequency noise. The measurement results demonstrate that the Hooge parameters are angular-dependent and they exhibit a linear relation with respect to the angular magnetoresistive susceptibility. It can be also observed that the Hooge parameters possess a higher value when the Conetic MTJs are in the region of antiparallel state. These results indicate that the magnetic fluctuations in the ferromagnetic layers contribute to the low-frequency noise level in Conetic MTJ sensors.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering
- Low-frequency noise
- Magnetic sensors
- Magnetic tunnel junction (MTJ)