Effect of sputtering process on magnetic properties and crystal structure of Sm2Fe17Nx thin films

Hard magnetic Sm2Fe17Nx thin films were prepared by dc magnetron sputtering and subsequent nitrogenation process. The results show that the sputtering parameters determine the film composition, which determines the crystal structure and magnetic properties. When the gas pressure varies from 1.2 to 2.1 Pa and power varies from 40 to 60 W, higher Sm content (>11.3 at%) is obtained, giving rise to improved coercivity HC and remanence ratio MR/MS. The optimal HC of 2127.8 Oe and MR/MS of 0.53 are obtained when the gas pressure and power reach 1.2 Pa and 50 W, respectively. In addition, it is found that the pure single Sm2Fe17 phase can be observed when the ratio of Fe/Sm exceeds 7.1 by controlling the sputtering parameters to adjust the composition.