Microstructures and Magnetism of Different Oxides Separating FePt Grains via Ion-Beam Bombardment and Annealing

    • Chiu Yi-Lun
    • Department of Materials Science and Engineering, National Chung Hsing University, Taichung 402, Taiwan

    • Hsu Jen-Hwa
    • Department of Physics, National Taiwan University, Taipei 106, Taiwan
    • Pong Philip W. T.
    • Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong
    • Suzuki Takao
    • MINT Center, University of Alabama, Tuscaloosa, AL 35487, U.S.A.
    • Lin Ko-Wei
    • Department of Materials Science and Engineering, National Chung Hsing University, Taichung 402, Taiwan

Abstract

The effects of the fabrication methods and different capped oxide (SiO2 and TiO2) layers on the microstructure and magnetism of FePt thin films were studied. Both structural ordering ($S \sim 0.7$) from the fcc FePt phase to the fct FePt phase and magnetic hardening were observed in the annealed FePt/SiO2 thin films with a low substrate rotation speed ($S_{\text{r}} = 1$ rpm). However, only the annealed FePt/SiO2 thin films prepared with a high $S_{\text{r}}$ (10 rpm) exhibited isolated FePt grains separated by the grain boundary SiO2, as revealed by transmission electron microscopy and magnetometry. Furthermore, similar results in microstructures and magnetic properties were obtained after replacing the capped layer with TiO2. However, an enhanced order parameter ($S \sim 0.85$) and a smaller FePt grain size (${\sim}6.8$ nm), which are promising characteristics for ultrahigh-density magnetic recording, were achieved in the annealed FePt/TiO2 thin films; however, the annealed FePt/SiO2 thin films exhibited a larger grain size (${\sim}15$ nm). This indicates that TiO2 inhibits the grain growth of FePt more effectively than SiO2.

Journal

Jpn J Appl Phys  

Jpn J Appl Phys 49(12), 123001-123001-5, 2010-12-25 

The Japan Society of Applied Physics

Codes

  • NII Article ID (NAID) :
    150000053380
  • NII NACSIS-CAT ID (NCID) :
    AA12295836
  • Text Lang :
    EN
  • Journal Type :
    大学紀要
  • ISSN :
    0021-4922
  • NDL Article ID :
    10928727
  • NDL Source Classification :
    ZM35(科学技術--物理学)
  • NDL Call No. :
    Z53-A375
  • Databases :
    NDL  JSAP/JPS 

Share