Crystal anisotropy implications on the intrinsic magnetic and optical properties in van der Waals FePS3

Ellenor Geraffy; Shahar Zuri; Milosz Marcin Rybak; Faris Horani; Adam K. Budniak; Yaron Amouyal; Magdalena Birowska; Efrat Lifshitz

arXiv · 2208.10890

Crystal anisotropy implications on the intrinsic magnetic and optical properties in van der Waals FePS3

Ellenor Geraffy·Shahar Zuri·Milosz Marcin Rybak·Faris Horani·Adam K. Budniak·Yaron Amouyal·Magdalena Birowska·Efrat Lifshitz

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Abstract

Antiferromagnetic (AFM) FePS3 has gained significant interest recently for its potential applications in spin-related devices. A single layer is comprised of a honeycomb network, stabilized by long-range spin-exchange interactions, with a zigzag or Neel arrangement of the Fe-atoms. This study exposed, for the first time, a strong impact of lateral crystal distortion on the magnetic arrangement and optical properties of FePS3. This impact was deciphered by correlating photoluminescence (PL) observations with single-crystal XRD which uncovered anisotropy in the a/b crystallographic plane. Thus, induceing a breakage in the inversion symmetry in FePS3 causing changes in it's electronic and optical transitions. The MPL observations exhibited an unexpected band-edge circularly polarized recombination emission, while off-band-edge transitions were linearly polarized. Also, temperature-dependent MPL measurements reflected zigzag-AFM at low temperatures and the coexistence of zigzag or Neel at mid temperatures. Theoretical calculation implementing anisotropy in spin-exchange interactions among Fe atom's nearest neighbors revealed stabilized zigzag arrangement tilted away from the a-axis. Furthermore, DFT calculations of the electronic band-edge predicted split states in degenerate symmetric points (K+/K-) for zigzag structure and non-degenerate for the Neel arrangement. Highlighting the importance of the inclusion of a crystallographic anisotropy parameter for the simulation of the experimental observations.

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Ellenor Geraffy, Shahar Zuri, Milosz Marcin Rybak, Faris Horani, Adam K. Budniak, Yaron Amouyal, Magdalena Birowska, Efrat Lifshitz. 2024-05-06. Crystal anisotropy implications on the intrinsic magnetic and optical properties in van der Waals FePS3. https://arxiv.org/abs/2208.10890

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