  The magnetic anisotropy (MA) of Mo/Au/Co0.9Fe0.1/Au/MgO(0.7 - 3
nm)/Au/Co0.9Fe0.1/Au heterostructure has been investigated at room temperature
as a function of MgO layer thickness (tMgO). Our studies show that while the MA
of the top layer does not change its character upon variation of tMgO, the
uniaxial out-of-plane MA of the bottom one undergoes a spin reorientation
transition at tMgO of about 0.8 nm, switching to the regime where the
coexistence of in- and out-of-plane magnetization alignments is observed. The
magnitudes of the magnetic anisotropy constants have been determined from
ferromagnetic resonance and dc-magnetometry measurements. The origin of MA
evolution has been attributed to a presence of an interlayer exchange coupling
(IEC) between Co0.9Fe0.1 layers through the thin MgO film.
