Improvement of the uniformity and dipole ferromagnetism in Co nanodots assemblies on Pb/Si(111) via step tuned dimensionality variation.
We fabricated quasi-one-dimensional Co nanochain assemblies and two-dimensional Co nanodot assemblies on Pb/Si(111) substrates by step decoration. The morphology and magnetic properties of these two kinds of Co nanodot assemblies were investigated by in situ scanning tunneling microscopy and magneto-optical Kerr effect measurements. It was found that the steps cannot only improve the uniformity of the Co nanodots, but also increase the critical temperature T(c). Monte Carlo simulation indicates that the ferromagnetism mainly originates from the dipolar interactions and the critical temperature T(c) can be enhanced by introducing an in-plane uniaxial magnetic anisotropy via the step tuned dimensionality variation of the nanodot assemblies.
State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China.
Ya-Peng
YP
Fang
Wei
W
He
Hai-Feng
HF
Du
Hao-Liang
HL
Liu
Qiong
Q
Wu
Xiang-Qun
XQ
Zhang
Hai-Tao
HT
Yang
Zhao-Hua
ZH
Cheng
Jian
J
Shen