Polarized neutron reflectometry study of Fe16N2 with Giant Saturation   Magnetization prepared by N Inter-diffusion in Annealed Fe-N Thin Films
  We report a synthesis route to grow iron nitride thin films with giant saturation magnetization (Ms) through an N inter-diffusion process. By post annealing Fe/Fe-N structured films grown on GaAs(001) substrates, nitrogen diffuses from the over-doped amorphous-like Fe-N layer into strained crystalline Fe layer and facilitates the development of metastable Fe16N2 phase. As explored by polarized neutron reflectometry, the depth-dependent Ms profile can be well described by a model with the presence of a giant Ms up to 2360 emu/cm3 at near-substrate interface, corresponding to the strained regions of these annealed films. This is much larger than the currently known limit (Fe65Co35 with Ms \sim 1900 emu/cm3). The present synthesis method can be used to develop writer materials for future magnetic recording application. 
Nian Ji, Valeria Lauter, Hailemariam Ambaye, Xiaowei Zhang, Sarbeswar   Sahoo, Mike Kautzky, Mark Kief and Jian-Ping Wang
cond-mat.mtrl-sci