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.
Fang
Ya-Peng
YP
State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China.
He
Wei
W
Du
Hai-Feng
HF
Liu
Hao-Liang
HL
Wu
Qiong
Q
Zhang
Xiang-Qun
XQ
Yang
Hai-Tao
HT
Cheng
Zhao-Hua
ZH
Shen
Jian
J