Epitaxial growth of ferromagnetic CoxFe4−xN thin films on SrTiO3 (001) and magneticproperties

摘要

We formed CoxFe4−xN (0≤x≤2.9) epitaxial thin films on SrTiO3 (001) substrates by molecular beam epitaxy supplying solid Co and Fe and a radio frequency N2 plasma, simultaneously. The composition ratio of Co/Fe in CoxFe4−xN was controlled by changing the weight ratio of Co to Fe flakes in the crucible of the Knudsen cell used. Epitaxial growth of CoxFe4−xN thin films were confirmed by reflection high-energy electron diffraction and θ–2θ X-ray diffraction patterns. Magnetization versus magnetic field curves measured at room temperature using a vibrating sample magnetometer showed that the axis of easy magnetization was changed from [100] to [110] with increasing x in CoxFe4−xN.