Magnetic microstructures in nano-granular CoPt-Al-O thin films studied by electron holography and Lorentz microscopy

Author

Park, H.S. ; Shindo, D. ; Mitani, S. ; Takanashi, K.

Author_Institution

Inst. for Multidisciplinary Res. for Adv. Mater., Tohoku Univ., Sendai, Japan

fYear

2005

fDate

4-8 April 2005

Firstpage

197

Lastpage

198

Abstract

TEM measurements are carried out on CoPt-Al-O thin films. CoPt-based nanocrystalline phases are found surrounded by Al₂O₃-based amorphous phases, showing nano-granular structures. Domain walls like fishbone are also observed in Lorentz microscope images of the nano-granular films. These domain walls disappear as the applied magnetic field increases. Further in the reconstructed phase images (holograms), it is found that the density of lines of magnetic flux increases with the increase in the magnetic field, indicating a mixed-phase state of the ferromagnetic and superparamagnetic phases.

Keywords

aluminium compounds; cobalt alloys; electron holography; ferromagnetic materials; granular structure; magnetic domain walls; magnetic flux; magnetic structure; magnetic thin films; nanostructured materials; noncrystalline structure; platinum alloys; superparamagnetism; transmission electron microscopy; CoPt-Al-O; Lorentz microscope images; Lorentz microscopy; amorphous phases; domain walls; electron holography; ferromagnetic phase; magnetic flux; magnetic microstructures; mixed-phase state; nanocrystalline phases; nanogranular thin films; reconstructed phase images; superparamagnetic phase; transmission electron microscopy; Amorphous materials; Electron microscopy; Holography; Magnetic domain walls; Magnetic fields; Magnetic films; Magnetic force microscopy; Micromagnetics; Transistors; Transmission electron microscopy;

fLanguage

English

Publisher

ieee

Conference_Titel

Magnetics Conference, 2005. INTERMAG Asia 2005. Digests of the IEEE International

Print_ISBN

0-7803-9009-1

Type

conf

DOI

10.1109/INTMAG.2005.1463527

Filename

1463527