The room-temperature wall energy&sgr;w=4.0×10−3 J/m2of an exchange-coupledTb19.6Fe74.7Co5.7/Dy28.5Fe43.2Co28.3double layer stack can be reduced by introducing a soft magnetic intermediate layer in between both layers exhibiting a significantly smaller anisotropy compared to Tb–FeCo and Dy–FeCo.&sgr;wwill decrease linearly with increasing intermediate layer thickness,dIL,until the wall is completely located within the intermediate layer fordIL⩾dw,wheredwdenotes the wall thickness. Thus,dwcan be obtained from the plot&sgr;wversusdIL.We determined&sgr;wanddwon Gd–FeCo intermediate layers with different anisotropy behavior (perpendicular and in-plane easy axis) and compared the results with data obtained from Brillouin light-scattering measurements, where exchange stiffness,A,and uniaxial anisotropy,Ku,could be determined. With the knowledge ofAandKu,wall energy and thickness were calculated and showed an excellent agreement with the magnetic measurements. A ten times smaller perpendicular anisotropy ofGd28.1Fe71.9in comparison to Tb–FeCo and Dy–FeCo resulted in a much smaller&sgr;w=1.1×10−3 J/m2anddw=24 nmat 300 K. AGd34.1Fe61.4Co4.5with in-plane anisotropy at room temperature showed a further reduced&sgr;w=0.3×10−3 J/m2anddw=17 nm.The smaller wall energy was a result of a different wall structure compared to perpendicular layers. ©1997 American Institute of Physics.