Phase separation and ferromagnetic transition inB-site substitutedNd1/2Ca1/2MnO3

$B$-site substitution effects on the structural and magnetic properties are investigated in ${\mathrm{Nd}}_{1/2}{\mathrm{Ca}}_{1/2}$$({\mathrm{Mn}}_{0.97}{M}_{0.03})$${\mathrm{O}}_{3}$ $(M=\mathrm{Al},$ Zn, Sc, Fe, Ni, Co, and Cr). With decreases of temperature below $\ensuremath{\sim}200 \mathrm{K},$ these compounds transform into a two-phase state. With further decrease of temperature below $\ensuremath{\sim}100 \mathrm{K},$ the Cr-, Co-, and Ni-doped compounds show the ferromagnetic transition, while the other compounds show only the antiferromagnetic component. We discuss these dopant-dependent ferromagnetic transition in terms of the effective one-electron bandwidth of the ${e}_{g}$ band.