  Thin magnetic multilayered films containing FePt have attracted a lot of
attention recently due to their possible usage in ultra-high density magnetic
storage. Although structure defects play a dramatic role in the magnetization
process and influence magnetic properties in general this dependence haven't
been studied thoroughly. The main aim of this work was to perform theoretical
investigation of the magnetic properties of FePt and Fe/FePt thin films with
high coercivity with respect to the structure defects such as anisotropy
constant, magnetization saturation, exchange constant fluctuations and easy
axis deviation. For selected defect patterns the coercive field dependence on
layer thicknesses was analysed. Numerical study of the bilayer with hard
magnetic layer having the planar anisotropy was carried on using micromagnetic
calculations. Values of layers thickness have been found optimal for
perspective applications, the dependence of the hysteresis loop shape upon the
magnetization process has been shown and analysed.
