In this work a comparative systematic study of the crystal structure and magnetic properties of Fe50Mn50/(Fe, Co, Ni, Fe20Ni80, Fe11Ni89, Co30Ni70) films in as-deposited state and after subsequent vacuum thermomagnetic treatment at temperatures up to 400 degrees C was performed. Thermally induced changes in magnetic properties are described quantitatively and critical role of the interlayer diffusion leading to partial or complete (for Co layer) destruction of the antiferromagnetic layer is demonstrated. The result of such compositional changes is a sig-nificant decrease or disappearance of exchange bias.