Growth, structure, and magnetism of γ -phase Mn ultrathin films on Cu 3 Au (100)

Abstract

Ultrathin γ -phase (face-center cubic) Mn films were prepared by epitaxial growth on Cu3 Au (100). Kinematic analysis of low energy electron diffraction IV showed a structure transformation of Mn films from nearly face-center cubic to face-center tetragonal with increasing coverage. No ferromagnetic signal in Mn Cu3 Au (100) was observed. For 21 ML capping film of Fe on Mn films, the hysteresis loop of Fe was biased. The bias field for 21 ML Fe15 ML Mn Cu3 Au (100) was ~200 Oe at 110 K with the blocking temperature Tb ~300 K. This observation of exchange bias substantiates the theoretical prediction of antiferromagnetism in γ -phase Mn. © 2005 American Institute of Physics.