(LaMn3Ni2Mn2O12: An A- and B-Site Ordered Quadruple Perovskite with A-Site Tuning Orthogonal Spin Ordering

Y. Y. Yin, M. Liu, J. H. Dai, X. Wang, L. Zhou, H. B. Cao, C. dela Cruz, C. T. Chen, Y. J. Xu, X. Shen, R. C. Yu, J. A. Alonso, A. Munoz, Y. F. Yang, C. Q. Jin, Z. W. Hu and Y. W. Long

Chemistry of Materials, 28, 8988 (2016)


A new oxide, LaMn3Ni2Mn2O12, was prepared by high-pressure and high-temperature synthesis methods. The compound crystallizes in an AA′3B2B′2O12-type A-site and B site ordered quadruple perovskite structure. The charge combination is confirmed to be LaMn3+3Ni2+2Mn4+2O12, where La and Mn3+ are 1:3 ordered at the A and A′sites and the Ni2+ and Mn4+ are also distributed at the B and B′ sites in an orderly fashion in a rocksalt-type manner, respectively. A G-type antiferromagnetic ordering originating from the A′-site Mn3+ sublattice is found to occur at TN ≈ 46 K. Subsequently, the spin coupling between the B-site Ni2+ and B′-site Mn4+ sublattices leads to an orthogonally ordered spin alignment with a net ferromagnetic component near TC ≈ 34 K. First-principles calculations demonstrate that the A′-site Mn3+ spins play a crucial role in determining the spin structure of the B and B′ sites. This LaMn3Ni2Mn2O12 provides a rare example that shows orthogonal spin ordering in the B and B′ sites assisted by ordered A-site magnetic ions in perovskite systems.