2018/08/28 by R. D. Johnson, Roger D. Johnson, D. D. Khalyavin +13 · 2 citations
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Magnetic and transport properties of perovskites and related materials #Multiferroics and related materials #Strongly Correlated Electrons (cond-mat.str-el) #Thermal Expansion and Ionic Conductivity #cond-mat.str-el
paper · pdf · doi:10.48550/arxiv.1808.09155
arxiv created 2018/08/28 · openalex publication_date 2018/08/28 · arxiv updated 2018/08/29 · openalex created_date 2018/09/07 · openalex updated_date 2026/07/28
We report a neutron powder diffraction study of RMn7O12 quadruple perovskite manganites with R = La, Ce, Nd, Sm, and Eu. We show that in all measured compounds concomitant magnetic ordering of the A and B manganese sublattices occurs on cooling below the N\mathrm\acuteeel temperature. The respective magnetic structures are collinear, with one uncompensated Mn3+ moment per formula unit as observed in bulk magnetisation measurements. We show that both LaMn7O12 and NdMn7O12 undergo a second magnetic phase transition at low temperature, which introduces a canting of the B site sublattice moments that is commensurate in LaMn7O12 and incommensurate in NdMn7O12. This spin canting is consistent with a magnetic instability originating in the B site orbital order. Furthermore, NdMn7O12 displays a third magnetic phase transition at which long range ordering of the Nd sublattice modifies the periodicity of the incommensurate spin canting. Our results demonstrate a rich interplay between transition metal magnetism, orbital order, and the crystal lattice, which may be fine tuned by cation substitution and rare earth magnetism.