Lorentz TEM imaging of stripe structures embedded in a soft magnetic matrix

N\'eel walls in soft magnetic NiFe/NiFeGa hybrid stripe structures surrounded by a NiFe film are investigated by high resolution Lorentz transmission electron microscopic imaging. An anti-parallel orientation of magnetization in 1000 nm wide neighboring unirradiated-irradiated stripes is observed by forming high angle domain walls during magnetization reversal. Upon downscaling the stripe structure size from 1000 nm to 200 nm a transition from a discrete domain pattern to an effective magnetic medium is observed for external magnetic field reversal. This transition is associated with vanishing ability of hosting high angle domain walls between adjacent stripes. The investigation also demonstrated the potentiality of Lorentz microscopy to image periodic stripe structures well under micron length-scale.Comment: 7 pages, 6 figure

MATLAB/simulink model of a MEMS accelerometer read-out circuit

AbstractMany future applications for accelerometers demand resolution below 1 mg together with low power dissipation far below 1 mW. Under this conditions, state-of-the-art switched-capacitor read-out circuits reach their limits and continuous-time operation seems to be the superior alternative. This work focuses on the modeling of a continuous-time read-out circuit and its calibration cycles. For achieving an approximation of the system properties in an early design phase including second order and parasitic effects a complex model of the whole system is derived. The developed model shows that the calibrations can successfully increase the dynamic range by 18 dB and suppress the offset of the capacitive MEMS accelerometer