Creating periodic vacancies in atomic chains within the individual layers of a 2D magnet

Van der Waals 2D magnetic materials have emerged as a novel platform that offers unique optoelectronic, magnetic, and quantum properties.¹ Such low-dimensional spin systems have vast potential in applications such as spintronics and nanoscale magnetic devices. Therefore, the ability to engineer the structure and defects with respect to magnetic, optical, and electronic properties is critical.

Here, we first confirm through scanning transmission electron microscopy that each layer of AgCrP₂S₆ contains alternating diatomic chains of silver and chromium.² We then show that irradiation with 200kV electrons introduces periodic vacancies on the silver diatomic chains and we study the phase transitions between different configurations with respect to electron dose. STEM simulation is performed to investigate the process of electron beam-induced periodic vacancy formation and the structural transition in more detail. Density functional theory calculations further quantify the pathway along which the structural change of the Ag diatomic chain occurs. Lastly, we relate the periodic vacancy formation to the magnetic properties of the material. We believe that this irradiation-induced transition may provide a pathway towards defining local defects and spin configurations in this and other analogous 2D magnets.

References

1. Gibertini, M., et al. Nat. Nanotechnol. 14, 408 (2019)

2. Selter S., et al. Crystals 11, 500 (2021)