Growth, structure, and magnetic properties of gamma '-Fe4N thin films

We have grown phase-pure, buffer-free, and epitaxial alpha-Fe and gamma'-Fe4N thin films by RE. magnetron sputtering onto MgO (100) substrates. The film thicknesses and densities have been determined with high accuracy by evaluating the Kiessig fringes of the X-ray reflectometry measurements. We have determined the volume saturation magnetization of gamma'-Fe4N with corresponding accuracy to be M-s = 1556 +/- 62 emu/cm(3) at 10K or 2.30 +/- 0.09 mu(B), per Fe atom. The Curie-temperature, T-C, of the gamma'-Fe4N thin films was 716 K. The slightly increased average magnetic moment per Fe atom of gamma'-Fe4N as compared to alpha-Fe is in agreement with literature values and attributed to the volume expansion of the unit cell.