Magnetic ordering of Mn and Ru in (La_0.52Ba_0.48) (Mn_0.51Ru_0.49)O₃

Neutron diffraction, de magnetization, and ac magnetic susceptibility measurements have been performed to study the magnetic properties of perovskite (La_0.52Ba_0.48)(Mn_0.51Ru_0.49)O ₃. The compound crystallizes into a cubic Pm3m symmetry with a lattice constant of a = 3.9661(4) Å at room temperature. Two anomalies, at around 160 and 60 K, can clearly be seen in the ac susceptibility results, with the peak positions for both anomalies shifting to a higher temperature as a dc magnetic field is applied. Neutron magnetic diffraction measurements show that the anomalies that occur at high and low temperatures are associated with the ferromagnetic ordering of the Mn and the Ru spins, respectively. The ordering temperatures for the Mn and Ru spins were found to be T_c (Mn) ≈ 195 K and T_c (Ru) ≈ 80 K, with a saturated moment of 〈μ_2-Mn〉= 2.21(5)μ_B for the Mn spins and 〈μ_2-Ru〉 = 1.00(5)μ_B for the Ru spins.