(Ca,K)(Zn,Mn)2As2: Ferromagnetic semiconductor induced by decoupled charge and spin doping in CaZn2As2

Abstract

We have successfully synthesized a novel diluted magnetic semiconductor (Ca1-2x K2x )(Zn1- x Mn x )2As2 with decoupled charge and spin doping. The substitutions of (Ca2+, K+) and (Zn2+, Mn2+) in the parent compound CaZn2As2 (space group P m1 (No. 164)) introduce carriers and magnetic moments, respectively. Doping only Mn into CaZn2As2 does not induce any type of long range magnetic ordering. The ferromagnetic ordering arise can only when K+ and Mn2+ are simultaneously doped. The resulted maximum Curie temperature reaches ∼7 K, and the corresponding coercive field is ∼60 Oe. The transport measurements confirm that samples with K and Mn co-doping still behave like a semiconductor.