New 2D fluxgate devices based on the phase modulation of magnetization rotation in AMR films

The AMR effect of single-domain film-resistors is being widely used for magnetic field and linear/angular displacement sensing. However, several constrains attributed to the repeatability of magnetization orientation limit the accuracy of such devices. There is a trade-off between device sensitivity and measurement repeatability; the anisotropy field HK affects both parameters in an inverse manner. To overcome such problems we propose the employment of AMR film-resistors as fluxgate devices. Using a rotating magnetic field vector as excitation, the anisotropic magnetoresistance material is kept continuously in saturation and a pseudo-super-paramagnetic behaviour is observed. Thus, the signal noise coming from Barkhausen jumps can be narrowed down to zero.