Crystal Anisotropy Implications on the Intrinsic Magnetism in van der Waals FePS₃

Ultrathin 2-D van der Waals (vdW) semiconductor materials have procured scientific and technological interest since the discovery of single layered graphene in 2004. Similar to graphene, transition metal trichalcogenides, with the general chemical formula MPX₃ (M= 1st row transition metals, X = chalcogenides), possess fast electron transport and strong spin orbit coupling without the drawback of no bandgap. These vdW inorganic lamellar compounds are characterized by strong intralayer covalent bonding and weak vdW interaction between adjacent layers. Transition metal atoms endow these materials with magnetic (either ferromagnetic or antiferromagnetic Neel, zigzag or stripy) and magneto-optical properties which can be utilized for new generation 2D magnets and opto-spintronic devices. Yet, the fundamental understanding of these materials as well as the manipulation of their intrinsic magnetism via external stimuli remains to be an unexplored endeavor.<br/>FePS₃ exhibits an overall zigzag antiferromagnetic ordering owing to its ferromagnetic Fe zigzag chains which are antiferromagnetically coupled to eachother, resulting in a high linear dichroism dependency which is direction depdenent. Additionally, the presence of crystallographic anisotropy is expected to yield significant impacts on its intrinsic magnetism and optical properties, particularly in the presence of external factors such as increasing temperature and external magnetic fields.<br/>In this talk,the correlation between the crytallographic anisiotropy and the optical and intrisic magnetic properties in FePS₃ is shown using temperature dependent photoluminescence (PL) and magneto-PL measurements. Additioanally, the presence of a metamagnetic phase transitions in FePS₃ upon inducing thermal and magnetic fluctuations using temperature dependent PL and linearly and circularly polarized magneto-PL.