Low frequency noise and magnetization fluctuation in AlOX magnetic tunnel junctions

Jhen-Yong Hong^1*, Chun-Yen Chen^1,2, Yu-Hui Tang², Dah-Chin Ling¹, Minn-Tsong Lin³, Cesar Gonzalez-Ruano⁴, Farkhad G. Aliev⁴

¹Department of Physics, Tamkang University, New Taipei City, Taiwan
²Department of Physics, National Central University, Taoyuan, Taiwan
³Department of Physics, National Taiwan University, Taipei city, Taiwan
⁴Department of Condensed Matter Physics, Universidad Autónoma de Madrid, Madrid, Spain

* Presenter:Jhen-Yong Hong, email:jyhong@mail.tku.edu.tw

Low-frequency magneto-resistive noise in AlOx magnetic tunnel junctions (MTJs) was studied at room temperature. The measured 1/f noise and the frequency-dependent Fano factor around the magnetic configuration reversal indicates that the magnetization fluctuation would be the main origin of the 1/f magnetic noise. Interestingly, random telegraph noise (RTN) was observed for both bare MTJs and MTJs with RS characteristics during the transition of magnetization switching. A comparison of the analysis with 1/f noise and magneto-resistive curve as a function of the magnetic field shows that the changes in magnetization dynamics are reflected in the RTN. The results suggest that the voltage-driven oxygen ions in the AlOx barrier could influence the interaction of transmission electrons from two relative magnetizations.

Keywords: Magnetic tunnel junctions (MTJs), Low-frequency noise (LFN), Random telegraph noise (RTN)