Competition between ferromagnetic and antiferromagnetic interactions by Cr doping at Mn sites in antiperovskite Mn_3−xCr_xZnN (0≤x≤0.5) compounds

The Cr doping effect on the lattice and magnetic properties in Mn_3−xCr_xZnN was reported in the antiferromagnetic intermetallic host material Mn₃ZnN. The lattice parameter decreases with the increase of the Cr concentration. Measurements of magnetization from 10 K to 350 K reveal that sharp antiferromagnetic (AFM)-to-paramagnetic (PM) transitions of the host material exist at 185 K (ZFC) and 177 K (FC). The peak is broadened clearly as the Cr doping was increased and when the Cr concentration exceeded 0.3, a significant ferromagnetic (FM) character was found to coexist with an AFM phase. At x=0.4 and 0.5, the M–H curves exhibit small magnetic hysteresis loop, indicating the dominant FM interactions in these samples. Also, a positive value of Weiss Temperature (Θ_W) at x=0.5 in H/M–T plot suggests that the FM interaction is dominant when the Cr doping increases.