Quasi-atom local chemistry that governs α-Mn structure

ORAL

Abstract

As opposed to the conventional free-electron-based theories of metals, a simple chemical theory, based on electrons occupying the quantum orbitals as the interstitial quasi-atoms (ISQs), has been successful to characterize the structure and stability of both high-symmetry (fcc, bcc, or hcp) and complex metals and metallic super hydrides [1,2]. Manganese (Mn) adopts a unique α (space group #217) structure under ambient conditions and up to high pressures of 165 GPa. The structural stability, phase transitions, and related phenomena in solids are typically driven by either magnetic or electronic properties. For a long time, the stability of α-Mn at high pressures has been attributed to the competing tendencies of its half-filled Mn-d band to maximize both the magnetic moment and bond strength. However, our calculations reveal that the magnetic moment of α-Mn becomes negligible above 55 GPa. In this study, we applied the quasi-atom theory to α-Mn. Electron localization function (ELF) and crystal orbital Hamiltonian population (COHP) analyses indicate that chemical interactions at the ISQ sites play a crucial role to stabilize the α-Mn structure.

[1] Y. Sun et. al, Proc. Natl. Acad. Sci. U.S.A. 120, e2218405120 (2023).

[2] Y. Sun and M. Miao, Chem 9, 443 (2023).

*M.M. and A.P. acknowledge the support of the DoD Research and Education Program for Historically Black Colleges and Universities and Minority-Serving Institutions (HBCU/MI) Basic Research Funding under grant No. W911NF2310232., the support of the National Science Foundation (NSF) funds DMR 1848141 and OAC 2117956, and the Camille and Henry Dreyfus Foundation.

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Presenters

  • Abhiyan Pandit

    • California State University, Northridge
    • Department of Chemistry and Biochemistry, California State University, Northridge, CA 91330, USA

Authors

  • Abhiyan Pandit

    • California State University, Northridge
    • Department of Chemistry and Biochemistry, California State University, Northridge, CA 91330, USA

  • Austin Ellis

    • CSUN
    • Department of Chemistry and Biochemistry, California State University, Northridge, CA 91330, USA

  • Yuchen Zhang

    • State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China

  • Kexin Zhang

    • State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China

  • Xiaoli Huang

    • State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China

  • Maosheng Miao

    • California State University, Northridge
    • Department of Chemistry and Biochemistry, California State University, Northridge, CA 91330, USA