Structural phase diagram, magnetism, and exchange-biased behavior of Fe films on Fex Mn1-x /Cu (001)

The fcc-bcc structural phase transition and the interlayer exchange-bias coupling in a Fe/ Fex Mn1-x /Cu (001) system are studied in a wide x range with different growth temperatures. For depositions of Fe at 150 K on the Fex Mn1-x layer with x<0.35, the transition occurs below 15 ML and the resulting bcc Fe films are ferromagnetic with exchange bias. The fcc Fe is stabilized up to 20 and 25 ML for the depositions on the Fex Mn1-x layer with x>0.35 at 150 and 300 K, respectively. Both fcc Fe films show no magnetic signal. The relation comprising the structure and magnetic coupling of the Fe films might be attributed to the x -dependent interface roughness at Fe/ Fex Mn1-x.