title: Tuning the ferromagnetic coupling of Fe nanodots on Cu(111) via dimensionality variation of the mediating electrons.
abstract: Using in situ magneto-optical Kerr effect measurements and phenomenological modeling, we study the tunability in both the magnetization anisotropy and magnetic coupling of Fe nanodots on a curved Cu(111) substrate with varying vicinity. We observe that, as the terrace width w decreases, the magnetization anisotropy increases monotonically, faster when w is smaller than the nanodot size d. In contrast, the magnetic coupling strength also increases until w approximately d, after which it decreases steeply. These striking observations can be rationalized by invoking the counterintuitive dimensionality variation of the surface electrons mediating the interdot coupling: the electrons are confined to be one dimensional (1D) when w > or = d, but become quasi-2D when w < d due to enhanced electron spillover across the steps bridged by the nanodots.
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: Lifeng
authors.initials: L
authors.lastname: Yin
authors.forename: Di
authors.initials: D
authors.lastname: Xiao
authors.forename: Zheng
authors.initials: Z
authors.lastname: Gai
authors.forename: Thomas Z
authors.initials: TZ
authors.lastname: Ward
authors.forename: Noppi
authors.initials: N
authors.lastname: Widjaja
authors.forename: G Malcolm
authors.initials: GM
authors.lastname: Stocks
authors.forename: Zhao-hua
authors.initials: ZH
authors.lastname: Cheng
authors.forename: E Ward
authors.initials: EW
authors.lastname: Plummer
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Zhang
authors.forename: Jian
authors.initials: J
authors.lastname: Shen