  We demonstrate the magnetization reversal features in NiFe/IrMn/NiFe
thin-film structures with 40% and 75% relative content of Ni in Permalloy in
the temperature range from 80 K to 300 K. At the descending branches of the
hysteresis loops, the magnetization reversal sequence of the two ferromagnetic
layers is found to depend on the type of NiFe alloy. In the samples with 75%
relative content of Ni, the bottom ferromagnetic layer reverses prior to the
top one. On the contrary, in the samples with 40% of Ni, the top ferromagnetic
layer reverses prior to the bottom one. These tendencies of magnetization
reversal are preserved in the entire range of temperatures. These distinctions
can be explained by the morphological and structural differences of interfaces
in the samples based on two types of Permalloy.
