Layer-number dependence of the magnetic properties of MnBi films

Abstract

We present the effect of multilayer deposition on the magnetic properties of MnBi thin films. The multilayered MnBi films were fabricated with alternating deposition of Bi and Mn with N (N=2–10) layers (L), followed by in situ thermal annealing. As N increases, the even-layered and odd-layered films show a similar layer-number-dependence of the magnetic properties, such as an increasing behavior for Hc and a concave-up behavior for Mr and (BH)max. Higher magnetic properties were obtained at 9L and 10L. According to the electron microscopy analyses, different morphologies and elemental distributions were observed at different N (e.g., smooth-surfaced MnBi film with Bi islands at 2L and uneven-surfaced MnBi film at 10L). The different distributions of microstructure and chemical components are associated with the layer-dependent magnetic properties of the MnBi films.