Magnetic properties and synthesis of high iHc Sm-Ti-Fe

Abstract

The room-temperature intrinsic coercive force, iHc, of the hard Sm-Ti-Fe phase observed in film samples has been measured as a function of composition. The maximum iHc observed at room temperature was 38.5 kOe for a composition Sm19Fe 73Ti8. Such samples were first made amorphous and then subsequently crystallized with an in-plane magnetic field, H s, applied. Tentative tetragonal lattice parameters have been assigned to this phase based on a fitting of 30 x-ray lines between 30°and 80°2θ for Cu radiation. The fitted tetragonal parameters are a=8.403 Å and c=12.401 Å. This high iHc Sm-Ti-Fe phase has not been observed in films that were directly crystallized onto heated substrates. The ferromagnetic Fe-rich phases in Sm-Ti-Fe samples have been synthesized by rf sputtering films onto heated as well as room-temperature substrates. The samples synthesized onto heated substrates were crystallized directly upon deposition, while the samples deposited onto room-temperature substrates were amorphous and were then subsequently crystallized. An in-the-film-plane magnetic field, Hs, was applied during the deposition as well as during the subsequent crystallization of amorphous film.