Study of magnetic iron nitride thin films deposited by high power impulse magnetron sputtering

In this work, we studied phase formation, structural and magnetic properties of iron-nitride (Fe-N) thin films deposited using high power impulse magnetron sputtering (HiPIMS) and direct current magnetron sputtering (dc-MS) techniques. The nitrogen partial pressure during deposition was systematically varied both in HiPIMS and dc-MS processes. Resulting Fe-N films were characterized for their microstructure, magnetic properties and nitrogen concentration. We found that HiPIMS deposited Fe-N thin films show improved soft magnetic properties and likely to possess globular nanocrystalline microstructure. In addition, it was found that the nitrogen reactivity with Fe get suppressed in HiPIMS discharge as compared to that in dc-MS plasma. Obtained results can be understood in terms of distinct plasma properties of HiPIMS discharge.