Berlin 2024 – scientific programme
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MA: Fachverband Magnetismus
MA 46: Poster II
MA 46.74: Poster
Thursday, March 21, 2024, 15:00–18:00, Poster C
A study of magnetic properties of face-sharing 3d manganese trimers — •Anzar Ali1,2, Sungkyun Choi1, and Masahiko Isobe2 — 1Sungkyunkwan University, Suwon 16419, Republic of Korea — 2Max Planck Institute for Solid State Research, Stuttgart Germany 70569
The emergence of a potentially conflicting molecular orbital state in correlated electron systems has recently garnered substantial attention in condensed matter physics, presenting a promising arena for uncovering novel electronic phases. Although this state has predominantly been explored in 4d and 5d transition metal oxides due to their extended orbital nature, our investigation focuses on 3d transition metal-based compounds featuring a face-sharing trimer. This study unveils systematic findings and a comprehensive understanding of two new 3d hexagonal perovskites, Ba4TaMn3O12 and Ba4NbMn3O12, wherein a face-sharing Mn trimer along the c-axis interacts within the hexagonal lattice. Surprisingly, effective magnetic moments suggest an S=2 trimer, while magnetic entropies propose a localized S=3/2 trimer. This apparent contrast finds resolution in a partial molecular orbital state, combining antiferromagnetically localized moments (S=3/2) and a delocalized one-electron (S=1/2) state within the trimer.
Ab-initio calculations reveal itinerant electron sharing and AF ordering in a Mn trimer, resulting in a unique coexistence of localized and delocalized electron states in a 3d material. To eliminate powder limitations, we stress the importance of growing single crystals using floating zone techniques to address disorder and impurity phases.
Keywords: Molecular Orbital State; Delocalized Electron; Antiferromagnet; Magnetic Susceptibility; Magnetic Entropy