Observation of Magnetic Domain Structure in FePt (001) Films by Electron Holography and Lorentz Microscopy

Abstract

Fig. 1 Typical image of magnetic force microscopy showing the stripe domains in the FePt(001) film. Magnetic domain structure of FePt(001) films, which show huge magnetocrystalline anisotropy, was observed by electron holography and Lorentz microscopy. Although these methods have advantages for the microanalysis of magnetic domains, e.g., the high spatial resolution, detection of the magnetic signal is rather difficult when the magnetization vector is parallel to the inci dent electron beam like the case of FePt (001) films. Here we demonstrate that the intensive observations are possible when the specimen is tilted in a microscope so that the magnetic flux perpendicular to the incident beam is generated. The holography ex periment using the cross_ sectioned specimen also provided useful information about the stray magnetic field of the FePt(001) films. (Received December 25, 2003; Accepted January 30, 2004) Keywords: transmission electron microscopy, magnetic recording, magnetic thin films, L1 0 _ type structure, magnetic domain wall, magnetic anisotropy Þ»ÝF\j[{é®ïÐú{à®wï ae 68 ª ae 5 (2004)315_ 319 ÁWuae[¿ìOkamoto ç 6,7) CShima ç 8,9) ÉaeènIÈÀ±ªÈ³êÄ èC¥aeÌ`óªúâK¥xÉå«Ë ¶·é±AEªñ

Lorentz microscopy mapping for domain wall structure study in L10 FePd thin films

“…In the case of thin foils with perpendicular magnetization (i.e. magnetization parallel to the electron path), this contrast can be obtained by tilting the sample to cause magnetic induction perpendicular to the beam [3,4,5]. However, in the perpendicular magnetical anisotropy (PMA) materials class, the domain walls (namely Bloch walls) exhibit an inplane magnetization component.…”