The magnetic ground state of perovskite structure ${\mathrm{CaRuO}}_3$ has been enigmatic for decades. Here we show that paramagnetic ${\mathrm{CaRuO}}_3$ can be made ferromagnetic by very small amounts of partial substitution of Ru by Ti. Magnetic hysteresis loops are observed at 5 K for as little as 2% Ti substitution. Ti is nonmagnetic and isovalent with Ru, indicating that the primary effect of the substitution is the disruption of the magnetic ground state of ${\mathrm{CaRuO}}_3$ through disorder. The data suggest that ${\mathrm{CaRuO}}_3$ is poised at a critical point between ferromagnetic and paramagnetic ground states.

• Received 4 December 2000

DOI:https://doi.org/10.1103/PhysRevB.63.172403