RESUMO
The stress-induced magnetic anisotropy can significantly affect giant magneto-impedance (GMI) effect of the soft magnetic film. This paper is devoted to the GMI effect of the single layer soft magnetic film implied without and with a stress. By simulating a physical model with MATLAB and COMSOL software, the impedance expression of the single layer soft magnetic film and the relation between external magnetic field and magnetic permeability are deduced. We observed that, without a stress, the sensitive region increased firstly and then decreased with the increasing of the excitation current frequency from 1 MHz to 200 MHz. While the film was subjected to the stress in the direction of the current with one end stressed, the stress on the film was gradually reduced from stressed end to free end. Also, the impedance change rate of the film changed when the stress was added, which is similar to the effect of adding a bias magnetic field on the film. More importantly, the addition of stress σ can induce the bias of the GMI measurement range and improve its sensitivity near zero magnetic fields. This may provide a new way for designing a GMI sensor with higher sensitivity and adjustable measurement range.
RESUMO
This study investigated the impact of electrode materials on HfO2-based RRAM devices. The research includes three types of electrode materials: (1) the electrodes with strong ability of oxygen reservoirs; (2) the electrode with poor ability of oxygen reservoirs; (3) the active electrode with injection ability. Through implementing different combinations of electrodes, three types of switching modes were obtained and the relative conduction mechanism was analyzed, as well as conduction model. Those studies may offer ways of using electrodes to control the resistive switching processes and fabricating the RRAM devices with good performance.