TY - JOUR
T1 - Magnetic configuration of submicron-sized magnetic patterns in domain wall motion memory
AU - Ohshima, Norikazu
AU - Numata, Hideaki
AU - Fukami, Shunsuke
AU - Nagahara, Kiyokazu
AU - Suzuki, Tetsuhiro
AU - Ishiwata, Nobuyuki
AU - Fukumoto, Keiki
AU - Kinoshita, Toyohiko
AU - Ono, Teruo
N1 - Funding Information:
The synchrotron radiation experiments were performed at SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) under the Nanotechnology Support Project of the Ministry of Education, Culture, Sports, Science and Technology. (Proposal Nos. 2006B0146 BL No.25SU and 2007A1903 BL No.25SU) The authors thank Dr. Shinya Kasai, Prof. Yoshinobu Nakatani, and Dr. Tetsuya Nakamura, and Dr. Yoshio Wantanabe for their useful discussions. The authors also thank Chuji Igarashi for preparing the samples and Dr. Koichi Izumi and Dr. Masafumi Nakada for their experimental support at SPring-8. A portion of this work was supported by NEDO.
PY - 2010/5/15
Y1 - 2010/5/15
N2 - We observed magnetic configuration and its change by external magnetic fields in submicron-sized U- and H-shaped NiFe patterns with an x-ray magnetic circular dichroism photoemission electron microscope. The microscope images showed the formation of a single domain wall (DW) with transverse structure at one corner of the U- and H-shaped patterns by applying the magnetic field from the oblique direction. By applying the magnetic field from the direction parallel to a horizontal bar in the patterns, the magnetic configuration in the U-shaped pattern was changed and four patterns were formed: (1) the DW moved from one trap site to another, (2) the DW moved beyond the trap site and formed a single domain, (3) the DW moved and stopped between the trap sites, and (4) the DW remained at the initial position. Only pattern (1) showed reversible DW motion, although pattern (2) was predominantly formed. In contrast, the magnetization configurations showed pattern (1), and reversible DW motion was observed for more than 80% of the H-shaped patterns. Micromagnetic simulation revealed that the DW in the U-shaped pattern was not sufficiently fixed at the corner and easily moved and vanished at the edge of the patterns because the magnetization in the two parallel bars rotated with a magnetic field. The DW was trapped with sufficient strength at the corner, and DW motion occurred only between the trap sites for the H-shaped patterns. The DW motion process was observed with an in situ magnetic field using the x-ray magnetic circular dichroism photoemission electron microscope and the process could be optimized by controlling the pattern shape.
AB - We observed magnetic configuration and its change by external magnetic fields in submicron-sized U- and H-shaped NiFe patterns with an x-ray magnetic circular dichroism photoemission electron microscope. The microscope images showed the formation of a single domain wall (DW) with transverse structure at one corner of the U- and H-shaped patterns by applying the magnetic field from the oblique direction. By applying the magnetic field from the direction parallel to a horizontal bar in the patterns, the magnetic configuration in the U-shaped pattern was changed and four patterns were formed: (1) the DW moved from one trap site to another, (2) the DW moved beyond the trap site and formed a single domain, (3) the DW moved and stopped between the trap sites, and (4) the DW remained at the initial position. Only pattern (1) showed reversible DW motion, although pattern (2) was predominantly formed. In contrast, the magnetization configurations showed pattern (1), and reversible DW motion was observed for more than 80% of the H-shaped patterns. Micromagnetic simulation revealed that the DW in the U-shaped pattern was not sufficiently fixed at the corner and easily moved and vanished at the edge of the patterns because the magnetization in the two parallel bars rotated with a magnetic field. The DW was trapped with sufficient strength at the corner, and DW motion occurred only between the trap sites for the H-shaped patterns. The DW motion process was observed with an in situ magnetic field using the x-ray magnetic circular dichroism photoemission electron microscope and the process could be optimized by controlling the pattern shape.
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U2 - 10.1063/1.3427555
DO - 10.1063/1.3427555
M3 - Article
AN - SCOPUS:77952964623
SN - 0021-8979
VL - 107
JO - Journal of Applied Physics
JF - Journal of Applied Physics
IS - 10
M1 - 103912
ER -