Magnetic properties of RRhO3 (R=rare earth)

RRhO3 (R=rare earth except Ce and Pm) was prepared by a solid-state reaction, and its crystallographic, magnetic, and electric properties were investigated. RRhO3 has an orthorhombic perovskite-type structure of the space group Pbnm. RRhO3 shows Curie-Weiss paramagnetism above 5 K. On the other hand, EuRhO3 shows antiferromagnetic behavior. The Rh3+ ion, which seems to be in the low-spin state, has a very small effective magnetic moment (Peff=0.295 μB/ion). The Peff value of the RRhO3 compounds shows the same dependence on the number of 4f electrons as the gJ value of the rare-earth ions. The rare-earth ions make a major contribution to the magnetic moment of RRhO3. The resistivity of all RRhO3 shows an activation-type (or semiconductor-like) temperature dependence