title: Strong magnetic enhancement in self-assembled multiferroic-ferrimagnetic nanostructures.
abstract: In the past decade, self-assembled vertical nano-heterostructures have drawn considerable attention because a high interface-to-volume ratio can be used to tailor or create functionalities. We have systematically investigated the magnetic properties of oxide heterostructures consisting of the CoFe2O4 nanopillars embedded in the BiFeO3 matrix using macroscopic magnetization measurements and element-selective soft X-ray absorption magnetic circular dichroism (XMCD) at the Co- and Fe-L2,3 edge. The magnetization and XMCD data show that the total ordered magnetic moment of Co(2+) in CoFe2O4-BiFeO3 nano-heterostructures is strongly enhanced. This study clearly indicates that the high interface-to-volume ratio vertical nanostructure creates a strong ferromagnetic and antiferromagnetic magnetic coupling via an interface. Furthermore, the magnetic coupling can be tuned in the multiferroic-ferrimagnetic self-assembled heterostructures by controlling the spacing between nanopillars.
authors.affiliation: National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan.
authors.forename: Ying-Jiun
authors.initials: YJ
authors.lastname: Chen
authors.forename: Ying-Hui
authors.initials: YH
authors.lastname: Hsieh
authors.forename: Sheng-Chieh
authors.initials: SC
authors.lastname: Liao
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Hu
authors.forename: Meng-Jie
authors.initials: MJ
authors.lastname: Huang
authors.forename: Wei-Cheng
authors.initials: WC
authors.lastname: Kuo
authors.forename: Yi-Ying
authors.initials: YY
authors.lastname: Chin
authors.forename: Tzeng-Ming
authors.initials: TM
authors.lastname: Uen
authors.forename: Jenh-Yih
authors.initials: JY
authors.lastname: Juang
authors.forename: Chih-Huang
authors.initials: CH
authors.lastname: Lai
authors.forename: Hong-Ji
authors.initials: HJ
authors.lastname: Lin
authors.forename: Chien-Te
authors.initials: CT
authors.lastname: Chen
authors.forename: Ying-Hao
authors.initials: YH
authors.lastname: Chu