Spin polarized tunneling as a probe for quantitative analysis of field dependent domain structure in magnetic tunnel junctions

Micromagnetic features appearing during the reversal of an artificial ferri magnet used as a hard layer of a magnetic tunnel junction are quantitativel y analyzed using the high sensitivity of the spin polarized tunnel current to magnetization fluctuations in the electrodes of the magnetic junctions. We propose an analytical model which takes into account different tunneling paths associated with local magnetization configurations. The model allows a quantitative correlation between the spin polarized transport characteri stics and the field-dependent domain structure. The results extracted from the tunnel magnetoresistance measurements are found to be in good agreement with the magnetic domain wall density extracted from magnetic force micros copy experiments. (C) 2001 American Institute of Physics.