Seminar by Hiroshi Kageyama "Mixed anion system: a new playground for chemists and physicists"

Seminar :

• Speaker: Hiroshi Kageyama, Dep. Energy and Hydrocarbon Chemistry, Kyoto University
• Date: Mon, Feb 20th
• Time: 14:00-15:00
• Venue: C016, Lab1
• Title: Mixed anion system: a new playground for chemists and physicists
• Abstract:

  Oxyhydrides, where the negatively charged hydrogen (H^–) coexists with the oxide anion, are expected to exhibit unprecedented properties that are unattainable in simple oxides. We show that the compressibility of SrVO₂H with alternate VO₂ and SrH layers is extraordinarily anisotropic: changes along c (V-H-V) are approximately twice those along a (V-O-V). The application of pressure also drives a transition from a two-dimensional Mott insulator to a Pauli paramagnetic metal. DET calculations reveal that the origin of the insulator-metal transition in SrVO₂H with low electron count (d²) differs markedly from that in the structurally related oxide, SrFeO₂ (d⁶). In SrVO₂H, the quasi-two-dimensional nature of the electronic structure is retained even in the highly compressed metallic phase, due to the lack of π-symmetry in H^–, or the orthogonal arrangement of V_dπ-H_s-V_dπ.

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We look forward to seeing many of you.

Theory of Quantum Matter Unit.