Dynamics and scaling behavior of magnetic domain in ferromagnetic nanothin films = 나노자성박막의 자구동역학 및 축척행동 연구

Cited 0 time in webofscience Cited 0 time in scopus
  • Hit : 321
  • Download : 0
The geometry and dynamics of magnetic domain in ultrathin ferromagnetic films and nanomultilayers are of fundamental interests, because the nature of domain and domain dynamics in these systems plays a key role in determining their important magnetic properties such as the domain formation and the magnetization reversal. From the technological point of view, interest in the geometry and dynamics of magnetic domain in these system has grown rapidly motivated by the possible application to information storage technology and upcoming magnetoelectronics. In this study, we have investigated the magnetic domain configurations, domain dynamics, and their scaling behavior in various ferromagnetic thin films such as Co, Co/Pd, and Co/Pt systems. To study the geometry and dynamics of magnetic domain, we have developed a high-performance magnetooptical microscope magnetometer (MOMM) system, which basically consists of a polarizing optical microscope, digital intensifying-CCD, and high-speed frame grabber to observe and store the image of magnetic domain via magnetooptical Kerr effect (MOKE). The system is capable of real-time domain observation with the spatial resolution of 0.4㎛ and the Kerr angle resolution of 0.1˚ at x1,000 magnification. By controlling the optical illumination path, we can provide an incident angle of 0 to 20˚ from the film normal and thus, we can observe magnetic domains of sample having perpendicular magnetic anisotropy via polar MOKE with normal incidence as well as sample having in-plane magnetic anisotropy via longitudinal MOKE with oblique incidence. By means of MOMM, we first report direct full-field observation of Barkhausen avalanches in Co polycrystalline thin films at criticality, where we can find dynamic scaling behavior of Barkhausen jump size. The Barkhausen jump size shows power-law scaling distribution with critical exponent τ=1.30±0.05, which is accordant to the two-dimensional prediction of the theoretical model originally prop...
Advisors
Shin, Sung-Chulresearcher신성철researcher
Description
한국과학기술원 : 물리학과,
Publisher
한국과학기술원
Issue Date
2002
Identifier
177210/325007 / 000975806
Language
eng
Description

학위논문(박사) - 한국과학기술원 : 물리학과, 2002.8, [ iii, 103 p. ]

Keywords

scaling behavior; domain dynamics; thin film; 나노자성박막; 축척행동; 자구동역학

URI
http://hdl.handle.net/10203/47303
Link
http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=177210&flag=dissertation
Appears in Collection
PH-Theses_Ph.D.(박사논문)
Files in This Item
There are no files associated with this item.

qr_code

  • mendeley

    citeulike


rss_1.0 rss_2.0 atom_1.0