2025/04/16 by Chakravarty, Shruti, Manuel, Pascal, Cervellino, Antonio +1
#FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Strongly Correlated Electrons (cond-mat.str-el)
paper · doi:10.48550/arxiv.2504.11863
We report a comprehensive investigation of the quadruple perovskite Ba4NaRu3O12, in which we discover a robust spin-lattice coupled ground state characterized by a long-range antiferromagnetic ordering at TN ∼ 257 K. The system's unique structural motif of three symmetrically distinct magnetic ions, including Ru dimers separated by non-magnetic layers, is intimately correlated with its magnetic behavior, as evidenced by temperature-dependent diffraction measurements and specific heat data. The powder neutron diffraction patterns at 13 K showed that the spins within the dimers are antiparallel, leading to a net zero moment contribution and a staggered arrangement of the triangular layers formed by the Ru moments within the corner-shared octahedra along the c-axis. The low-temperature specific heat revealed an extra boson peak contribution from optical modes with a maximum vibrational energy of ∼55cm-1. The charge transport exhibited variable-range hopping (VRH) behaviour below TN, with a stronger energy-dependence than expected from the Efros-Shklovskii model, suggesting the presence of multiparticle correlation effects.