Magnetic properties of the antiferromagnetic double perovskite Ba₂PrRuO₆

The ordered perovskite compound Ba₂PrRuO₆ is prepared and its magnetic properties are investigated. The Rietveld analysis of the neutron diffraction profiles measured at 150 K shows that the Pr³⁺ and Ru⁵⁺ ions are arranged with regularity over the six-coordinate B sites of the perovskite ABO₃ and that Ba₂PrRuO₆ belongs to space group P2₁/n, with a = 6.0063(5), b = 5.9863(4), c = 8.4677(7) Å and 90.04(2)°. The magnetic susceptibility and the heat capacity measurements show that this compound transforms to an antiferromagnetic state below 117 K. From the neutron diffraction patterns measured at 7 K, the magnetic structure is determined to be of Type I and the magnetic moments of Pr³⁺ and Ru⁵⁺ are estimated to be 2.2(1) and 2.0(2) µ_B, respectively. Their values are discussed on the basis of theoretical calculations for the crystal field splitting.