Layered transition metal dichalcogenides (TMDs) are attracting increasing attention because they exhibit unconventional magnetic properties due to crystal imperfections in their usually non-magnetic 2D structure. This work aims to investigate the magnetic response of self-engineered Se deficient TiSe2 thin films, synthesized using chemical vapour deposition. We demonstrate tunability of the ferromagnetic order with the introduction of Au atoms using low energy Au ion implantation, which works as a controlling knob to vary the stoichiometry of Se in TiSe2−x. The corresponding isothermal field-magnetization curves fit well with a modified Brillouin J function with J value of 1.5 for Ti3+, and 4 for Au3+, accounting for the diamagnetism that arises from Au implantation. We propose a qualitative model for the experimentally observed magnetization as a function of ion fluence, corroborated with high-resolution transmission electron microscopy. Depending on the Au nanoparticle size in the implanted samples, magnetization saturates faster at a much lower applied magnetic field than the pristine sample. Our findings hold potential to expand the range of 2D ferromagnetic materials for spintronics and magnetic sensing applications.
@article{arxiv.2202.01152,
title = {Defect Controlled Ferromagnetic Ordering in Au Implanted TiSe$_2$ Nanocrystals},
author = {Utkalika P. Sahoo and Spandan Anupam and Bidyadhar Das and Mrinal K. Sikdar and Laxmipriya Nanda and Pratap K. Sahoo},
journal= {arXiv preprint arXiv:2202.01152},
year = {2022}
}