Correlation Driven Magnetic Frustration and Insulating Behavior of TiF<sub>3</sub>

ORAL

Abstract

We investigate the halide perovskite TiF3, renowned for its intricate interplay between structure, electronic correlations, magnetism, and thermal expansion. Despite its simple structure, understanding its low-temperature magnetic behavior has been a challenge. Previous theories proposed antiferromagnetic ordering. In contrast, experimental signatures for an ordered magnetic state are absent down to 10~K. Our current study has successfully reevaluated the theoretical modeling of TiF$_3$, unveiling the significance of strong electronic correlations as the key driver for its insulating behavior and magnetic frustration. In addition, our frequency-dependent optical reflectivity measurements exhibit clear signs of an insulating state. Analysis of the calculated magnetic data gives an antiferromagnetic exchange coupling with a net Weiss temperature of order 25 K as well as a magnetic response consistent with a S=1/2 local moment per Ti3+. Yet, the system shows no susceptibility peak at this temperature scale and appears free of long-range antiferromagnetic order down to 1 K. Extending ab initio modeling of the material to larger unit cells shows a tendency for relaxing into a non-collinear magnetic ordering, with a shallow energy landscape between several magnetic ground states, promoting the status of this simple, nearly cubic perovskite structured material as a candidate spin liquid.

[1] Gayanath W. Fernando, Donal Sheets, Jason Hancock, Arthur Ernst, R. Matthias Geilhufe, Correlation Driven Magnetic Frustration and Insulating Behavior of TiF3, arXiv:2310.12645 (2023)

[2] D. Sheets, K. Lyszak, M. Jain, J. Hancock, G. W. Fernando, I. Sochnikov, J. Franklin, and R. M. Geilhufe, Spin-1/2 Mott state in negative thermal expansion perovskite TiF3, in preparation (2023)

*We acknowledge support from the Swedish Research Council (No. 2022-03350), Chalmers University of Technology, the U.S. National Science Foundation (No. NSF-DMR-1905862), Fonds zur Förderung der Wissenschaftlichen Forschung (FWF) (Grant No. I 5384). We also acknowledge the computing resources provided by the Center for Functional Nanomaterials at Brookhaven National Laboratory (No. DE-SC0012704) and the Swedish National Infrastructure for Computing (SNIC).

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Publication: [1] Gayanath W. Fernando, Donal Sheets, Jason Hancock, Arthur Ernst, R. Matthias Geilhufe, Correlation Driven Magnetic Frustration and Insulating Behavior of TiF3, arXiv:2310.12645 (2023)
[2] D. Sheets, K. Lyszak, M. Jain, J. Hancock, G. W. Fernando, I. Sochnikov, J. Franklin, and R. M. Geilhufe, Spin-1/2 mott state in negative thermal expansion perovskite TiF3, submitted to PRB (2023)

Presenters

  • GAYANATH W FERNANDO

    • University of Connecticut

Authors

  • R. Matthias Geilhufe

    • Chalmers University
    • Chalmers Univ of Tech

  • GAYANATH W FERNANDO

    • University of Connecticut

  • Donal Sheets

    • University of Connecticut

  • Arthur Ernst

    • Johannes Kepler University, Altenbergerstraβe 69, Linz 4040, Austria
    • Johannes Kepler University Linz
    • Max Planck Institute of Microstructure Physics

  • Jason N Hancock

    • University of Connecticut