Title :
Microstructure and Magnetic Properties of FePt-MO
Granular Films
Author :
Shiroyama, Taisuke ; Abe, Takashi ; Takahashi, Y. ; Hono, Kazuhiro
Author_Institution :
Nat. Inst. for Mater. Sci., Tsukuba, Japan
Abstract :
We have studied the microstructures and magnetic properties of FePt-segregant granular films to achieve an ideal media structure on glass substrates for thermally assisted magnetic recording. Although FePt-C granular films show an excellent in-plane structure, it does not have a good surface roughness. Meanwhile, FePt-SiO2 granular films have a smooth surface and an interconnected in-plane microstructure. Therefore, to obtain both a surface with a small roughness and well-isolated small columnar grains, we have selected four metal oxides, MOx (M = Nb, W, Zr and Al) as segregants, which are expected to have a driving force for the phase separation between FePt-C and FePt-SiO2 based on thermodynamic evaluation. In this paper, we introduce the ground for selecting these materials as segregants and then show the microstructure and magnetic properties of FePt-MOx granular films.
Keywords :
aluminium compounds; carbon; crystal microstructure; discontinuous metallic thin films; iron alloys; magnetic thin film devices; magnetic thin films; niobium compounds; phase separation; platinum alloys; silicon compounds; surface roughness; thermomagnetic recording; tungsten compounds; zirconium compounds; FePt-AlOx; FePt-C; FePt-C granular films; FePt-NbOx; FePt-SiO2; FePt-WOx; FePt-ZrOx; FePt-segregant granular films; FePt-silica granular films; SiO2; columnar grains; driving force; glass substrates; in-plane structure; interconnected in-plane microstructure; magnetic properties; media structure; phase separation; smooth surface; surface roughness; thermally assisted magnetic recording; thermodynamic evaluation; Carbon; Force; Glass; Magnetic properties; Media; Microstructure; Niobium; FePt; granular film; thermally assisted magnetic recording;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2013.2239963