The electronic and magnetic properties of alloyed Ti1-xYxSe2 (Y=V, Cr, Mn; x= 0.11, 0.44, 0.89, 1.00) systems: Ab-initio calculations

Calculations using density functional theory (DFT) were performed to study the electronic and magnetic properties of alloyed Ti 1- x Y x Se 2 (Y=V, Cr, Mn; x = 0.11, 0.44, 0.89, 1.00) monolayer (ML) systems. The exchange correlation functional was treated using the generalized gradient approximation (GGA) and GGA+ U for the strongly correlated d electrons of the transition metals, using the Hubbard-like correction, U . Titanium diselenide (TiSe 2 ) ML was found to exhibit a nonmagnetic metallic nature in its pristine form. However, the alloyed Ti 1- x Y x Se 2 systems were found to exhibit metallic ferromagnetic ground-state structures. The total magnetic moment per formula unit (f.u.) of all alloyed Ti 1- x Y x Se 2 systems increased as a function of x . The Ti 1- x V x Se 2 systems exhibited 0.14, 0.50, 0.71, and 0.73 μ B /f.u., whereas, Ti 1- x Cr x Se 2 (Ti 1- x Mn x Se 2 ) systems yielded higher values of 0.27 (0.30), 1.07 (1.17), 1.99 (2.39), and 2.19 (2.17) μ B /f.u. for x = 0.11, 0.44, 0.89, and 1.00, respectively. These values were found to increase using GGA+ U with the same ferromagnetic behavior. The alloyed transition-metal atoms (V, Cr, and Mn) provided the major contribution to the magnetization of alloyed Ti 1- x Y x Se 2 MLs, which is promising for applications in ultra-thin magnetic recordings and spintronics. • Pristine TiSe 2 monolayer was metallic and non-magnetic but alloyed systems were metallic and magnetic. • Magnetic moment increased with alloy concentration. • Cr and Mn alloying produced significantly higher magnetic moments compared to V alloying. • The magnetization highlights the strong potential of alloyed TiSe 2 in spintronic applications.