Elemental moment variation of bcc FexMn1−x on MgO(001)

We report the growth, structural characterization, and electronic structure evolution of epitaxially grown bcc FexMn1−x on MgO(001). It is observed that the 20 nm thick FexMn1−x alloy films remained bcc from 0.65≤x≤1, much beyond the bulk stability range of 0.88≤x≤1. X-ray absorption spectroscopy and X-ray magnetic circular dichroism show that both the Fe and Mn L3 binding energies slightly increase with Mn incorporation and that the elemental moment of Fe in the 20 nm crystalline bcc alloy film remain nearly constant, then shows a dramatic collapse near x~0.84. The Mn MCD intensity is found to be small at all compositions that exhibit ferromagnetism