Defects Engineering Induced Ultrahigh Magnetization in Rare Earth Element Nd‐doped MoS <sub>2</sub>
Xiang Ding, Xiangyuan Cui, Ahmed Sohail, Peter P. Murmu, J. Kennedy, Nina Bao, Jun Ding, Rong Liu, Mingli Peng, Lan Wang, Xueze Chu, Ajayan Vinu, Simon P. Ringer, Jiabao Yi
Abstract
Abstract Various concentrations (0, 0.5, 1, and 5 at%) of Nd are doped into MoS 2 single crystals via ion implantation. Experimental results reveal that Nd exists in the form of trivalent state when the doping concentration is below 5 at% and a variety of defects, such as sulfur and molybdenum vacancies, are formed in Nd‐doped MoS 2 . Compared to pure MoS 2 that only shows diamagnetism, Nd doping successfully induces room‐temperature ferromagnetic ordering. Extremely high magnetization (1640 emu cm −3 ) is observed in 1 at% Nd‐doped MoS 2 . First‐principles density functional theory calculations suggest that the various structural defects, including substitutions, vacancies, interstitials, antisites, and their complexes, are magnetic possessing large spin moments. The defects coupled with Nd dopants ferromagnetically may form the bound magnetic polarons to induce ferromagnetic ordering. The work has demonstrated that through defects engineering and rare earth element doping, extremely high magnetization materials can be achieved in layered structured materials. On the other hand, though the experiment work is done by implanting MoS 2 single crystals, theoretical calculations indicate that 2D MoS 2 with bilayers or a few layers can also result in ultrahigh magnetization.