(La1−xBax)(Zn1−xMnx)AsO: A two-dimensional 1111-type diluted magnetic semiconductor in bulk form

Abstract

We report the synthesis and characterization of a bulk diluted magnetic semiconductor (La${}_{1\ensuremath{-}x}$Ba${}_{x}$)(Zn${}_{1\ensuremath{-}x}$Mn${}_{x}$)AsO (0 $\ensuremath{\leqslant}$ $x$ $\ensuremath{\leqslant}$ 0.2) with a layered crystal structure identical to that of the 1111-type FeAs superconductors. No ferromagnetic order occurs with (Zn,Mn) substitution in the parent compound LaZnAsO without charge doping. Together with carrier doping via (La,Ba) substitution, a small amount of Mn substituting for Zn results in ferromagnetic order with ${T}_{C}$ up to $\ensuremath{\sim}$40 K, although the system remains semiconducting. Muon spin relaxation measurements confirm the development of ferromagnetic order in the entire volume, with the relationship between the internal field and ${T}_{C}$ consistent with the trend found in (Ga,Mn)As and the 111-type Li(Zn,Mn)As and the 122-type (Ba,K)(Zn,Mn)${}_{2}$As${}_{2}$ systems.