Dresden 2026 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 49: Correlated Electrons: Charge Order
TT 49.8: Talk
Wednesday, March 11, 2026, 12:30–12:45, HSZ/0101
Controlling metastable charge-ordered states in δ-Ag2/3V2O5 — •Masahiko Isobe1, Taisei Kubo2, Naoyuki Katayama2, and Robert E. Dinnebier1 — 1Max Planck Institute for Solid State Research, Heisenbergstrasse 1, D-70569 Stuttgart, Germany — 2Department of Applied Physics, Nagoya University, Nagoya 464-8603, Japan
Vanadium bronzes have attracted much interest as a playground of various quantum phenomena. They are essentially mixed valent oxides where metallic conductivity and novel phenomena with spin, charge and orbital degrees of freedom can be exhibited. Recently we have investigated the delta-phase of vanadium bronze, focusing on the phase transition in δ-Ag2/3V2O5 which shows characteristic super-cooling effects. The structure consists of double trellis layer formed by edge/corner-shared VO6 octahedra and Ag ions located between the layers. We have observed the phase transition at around 230 K accompanied by jumps of magnetic susceptibility and resistivity. Structural analysis of the low-temperature triclinic phase reveals that Ag ion order and Vanadium dimer formation. Below the transition temperature the magnetic susceptibility shows a broad maximum around 110 K followed by spin gap behavior. We conclude that the phase transition in δ-Ag2/3V2O5 is a charge order into V4+ and V5+ induced by Ag ion order. The V4+ ions form dimers with the spin-gapped ground state. Also it can be super-cooled down to the lowest temperature by rapid cooling.
Keywords: vanadate; charge order; charge glass