title: The synthesis and characterization of 1 1 1 1 type diluted ferromagnetic semiconductor (La(1-x)Ca(x))(Zn(1-x) Mn(x))AsO.
abstract: We report the synthesis and characterization of a bulk form diluted magnetic semiconductor, (La(1-x)Ca(x))(Zn(1-y) Mn(y))AsO, with a layered crystal structure isostructural to that of the 1 1 1 1 type Fe-based high-temperature superconductor LaFeAsO and the antiferromagnetic LaMnAsO. With Ca and Mn codoping into LaZnAsO, the ferromagnetic ordering occurs below the Curie temperature T(c) ∼30 K. Taking advantage of the decoupled charge and spin doping, we investigate the influence of carrier concentration on the ferromagnetic ordering state. For a fixed Mn concentration of 10%, T(c) increases from 24 K to 30 K when the Ca concentration increases from 5% to 10%. Further increase of Ca concentration reduces both the coercive field and saturation moment. Muon spin relaxation measurements confirm the ferromagnetically ordered state, and clearly demonstrate that La(1-x)Ca(x))(Zn(1-y) Mn(y))AsO shares a common mechanism for the ferromagnetic exchange interaction with (Ga,Mn)As. Neutron scattering measurements show no structural transition in (La(0.90)Ca(0.10))(Zn(0.90)Mn(0.10)) AsO below 300 K.
authors.affiliation: Department of Physics, Zhejiang University, Hangzhou 310027, People's Republic of China. Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, People's Republic of China.
authors.forename: Cui
authors.initials: C
authors.lastname: Ding
authors.forename: Shengli
authors.initials: S
authors.lastname: Guo
authors.forename: Yao
authors.initials: Y
authors.lastname: Zhao
authors.forename: Huiyuan
authors.initials: H
authors.lastname: Man
authors.forename: Licheng
authors.initials: L
authors.lastname: Fu
authors.forename: Yilun
authors.initials: Y
authors.lastname: Gu
authors.forename: Zhouyang
authors.initials: Z
authors.lastname: Wang
authors.forename: L
authors.initials: L
authors.lastname: Liu
authors.forename: B A
authors.initials: BA
authors.lastname: Frandsen
authors.forename: S
authors.initials: S
authors.lastname: Cheung
authors.forename: Y J
authors.initials: YJ
authors.lastname: Uemura
authors.forename: T
authors.initials: T
authors.lastname: Goko
authors.forename: H
authors.initials: H
authors.lastname: Luetkens
authors.forename: E
authors.initials: E
authors.lastname: Morenzoni
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhao
authors.forename: F L
authors.initials: FL
authors.lastname: Ning