We have investigated electron- and hole-doping effects on $A$-site ordered perovskite manganite NdBaMn$_2$O$_6$, which has the $A$-type (layered) antiferromagnetic (AFM) ground state. Electrons (holes) are introduced by partial substitution of Ba$^{ 2+}$ (Nd$^{ 3+}$) with Nd$^{ 3+}$ (Ba$^{ 2+}$). Electron-doping generates ferromagnetic (FM) clusters in the $A$-type AFM matrix. With increasing the electron-doping level, the volume fraction of the FM phase or the number of the FM clusters is abruptly increasing. In contrast, the $A$-type AFM phase is robust against the hole-doping, and no FM correlation is observed in the hole-doped NdBaMn$_2$O$_6$.
Categories: cond-mat.str-el