Bubble domain in amorphous Nd-Fe-B magnetic films Jinlong Gao and Shaolong Tang Nanjing National Laboratory of Microstructures and Department of Physics, Nanjing University,Nanjing 210093,China

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Bubble domain in amorphous Nd-Fe-B magnetic
filmsJinlong Gao and Shaolong Tang Nanjing
National Laboratory of Microstructures and
Department of Physics,Nanjing University,Nanjing
210093,China
INTRODUCTION
Magnetic domain structure of different
kinds of amorphous NdFeB films was investigated
using MFM(Magnetic Force Microscopy), there are
generally strip domains.However, the
domain configuration changes by applying magnetic
field perpendicular to the plane,and these domain
patterns are stable after removing the
field. Especially, it is observed that the domain
pattern changes into bubbles after magnetization
of a specific magnetic field.
DISCUSSION
RESULTS
1.The transformation of magnetic domains after
magnetization of different magnetic field.
10µm10µm
2000Oe
4000Oe
5500Oe
2.The reversibility of domain patterns ,black
bubbles to white bubble.
FIG 1. Typical 2D and 3D topography image of the
amorphous film.
-5500Oe
-4000Oe
-2000Oe
3.Obviously, the amorphous Nd-Fe-B films show
out-of-plane anisotropy and controllable magnetic
structures, which have potential application in
magnetic recording and provide another approach
to study magnetic domain dynamics.
10µm10µm
10µm10µm
FIG 2. Different kinds of strip domains .(Domain
width-about 200nm)
EXPERIMENTAL METHOD

1. Magnetic sputtering, at low substrate
   temperature(300?), amorphous Nd-Fe-B films were
   deposited on substrate Si. And the thickness of
   the film is usually 200nm.
2. MFM(Magnetic Force Microscopy) with interleave
   mode on SPM. The topography and domain
   patterns can be measured at the same time.

10µm10µm
10µm10µm
FIG 3. The white and black bubble domains after
magnetization of a specific magnetic field.
This work is supported by Natural Science
Foundationof China Grant No.50771055