title: Highly ordered self-assembly with large area of Fe3O4 nanoparticles and the magnetic properties.
abstract: Monodisperse Fe3O4 nanoparticles (NPs) with narrow size distribution are synthesized by a high-temperature solution-phase method. The diameter of the as-synthesized NPs is tuned from 2 to 14 nm by varying the reaction conditions. Highly ordered superlattice structures of the Fe3O4 NPs with areas extending over 0.8 microm x 0.7 microm have been successfully obtained. The magnetic properties are investigated in their different states, such as in the solid state and diluted in wax with different concentrations. Some magnetic properties enhanced by increasing interparticle distances, such as the remanent magnetization and coercive field at low temperature, were noticed. Furthermore, we also observed that the saturation magnetization changed with temperature as expected. The preliminary explanation for the properties mentioned above is proposed.
authors.affiliation: Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China.
authors.forename: Tianzhong
authors.initials: T
authors.lastname: Yang
authors.forename: Chengmin
authors.initials: C
authors.lastname: Shen
authors.forename: Zian
authors.initials: Z
authors.lastname: Li
authors.forename: Huairuo
authors.initials: H
authors.lastname: Zhang
authors.forename: Congwen
authors.initials: C
authors.lastname: Xiao
authors.forename: Shutang
authors.initials: S
authors.lastname: Chen
authors.forename: Zhichuan
authors.initials: Z
authors.lastname: Xu
authors.forename: Dongxia
authors.initials: D
authors.lastname: Shi
authors.forename: Jianqi
authors.initials: J
authors.lastname: Li
authors.forename: Hongjun
authors.initials: H
authors.lastname: Gao