Molecular Beam Epitaxial Growth and Magnetic properties of Fe(001)/Mn$_{3}$N$_{2}$(010) Thin Films

Exchange bias systems have attracted considerable attention due to their importance to magnetic sensor technology. Considering that T$_{Neel}$ of Mn$_{3}$N$_{2}$ (T$_{N}$=652$ ^\circ$C) is less than T$_{Curie}$ of Fe (T$_{C}$=770 $^\circ$C), and also since Mn-Mn spacing of Mn$_{3}$N$_{2}$(010) ($\simeq$2.86 angstrom) is closely matched to the Fe-Fe spacing of Fe(001)(2.87 angstrom), it is therefore of great interest to explore Fe epitaxy on Mn3N2(010). We have grown thin Fe films on Mn$_{3}$N$_{2}$(010)/MgO(001) using molecular beam epitaxy at 150$ ^\circ$C, and then following by annealing at 450$ ^\circ$C for 10 minutes. The growth is monitored by reflection high-energy electron diffraction, which shows c(2x2) reconstructed surface for the as-grown sample, and a change to (1x1) after annealing. Annealing leads to a smoothening of the film surface.The epitaxial orientation have been determined to be Fe [100] (001)// Mn3N2[101] (010)//MgO[110](001). Annealed samples are transferred to the in situ analysis chamber for scanning tunneling microscopy studies. Images show smooth terraces and atomic-height steps. Vibrating sample magnetometry measurements found in-plane anisotropy and hysteresis loop shifting after field cooling. The work is supported by NSF9983816 and 0304314.