2018/11/01 by S. V. Streltsov, D. I. Khomskii · 6 citations
Materials Science · Physics and Astronomy · #Magnetic and transport properties of perovskites and related materials #Thermal Expansion and Ionic Conductivity #Advanced Condensed Matter Physics
paper · pdf · doi:10.1134/s0021364018220071
Recently synthesized Ba 4 NbMn 3 O 12 belong to cluster magnets that are systems with tightly bound groups of magnetic ions, in this case Mn 3 trimers. Such magnetic clusters can often be described by molecular orbitals, however strong electron correlations may invalidate this description. To understand the electronic and magnetic state of Ba 4 NbMn 3 O 12 we carried out ab initio calculations and show that this system is better described not in molecular orbitals picture, but as a system with electrons localized on the Mn ions, with strong intracluster and weaker inter-cluster exchange. The calculated spin of the Mn 3 trimer is S = 2, in agreement with the experiment. The predicted magnetic structure of Ba 4 NbMn 3 O 12 is that of ferromagnetic layers of Mn 3 trimers, stacked antiferromagnetically.