The effect of Ru-site dopants on the magnetic properties of CaRuO₃

The effects of Ru-site metal dopants on the low-temperature magnetization of CaRuO3 are reported. Dopants of two types are tested: those with closed d shells in their expected oxidation state (Al3+, Zn2+, Ti4+, V5+ and Pt2+), and those with unpaired d electrons (Mn4+, Fe3+, Co2+, Ni2+ and Cu2+) in their expected oxidation state. The results are consistent with the recent proposal that CaRuO3 is not a classical antiferromagnet, but rather is poised at a critical point between ferromagnetic and paramagnetic ground states. Ti, Fe, Mn and Ni doping result in ferromagnetic behaviour.