Doping and defect engineering induced extremely high magnetization and large coercivity in Co doped MoTe2
Journal of Alloys and Compounds
Magnetism in layered two dimensional materials has attracted extensive interest. In this work, a variety of concentrations of Co dopants (1, 2 and 4 at.%) were doped into MoTe2 single crystal by ion implantation. Magnetic results indicate that pure MoTe2 displays a diamagnetic behavior. A small amount of Co doping induces a very high saturation magnetization. 4 % Co doping exhibits a saturation magnetization as high as 2231 emu/cm3, higher than pure metallic Fe (1958 emu/cm3). In addition, an outsized coercivity of 11 kOe was also detected in the 2 at.% Co doped MoTe2 sample, which may be a consequence of doping-induced defects in the lattice structure, stress, anisotropic geometry of Co-Te ions and pinning effects by the defects in-between the ions. First principles density functional theory calculations reveal that doping-induced structural defects, including substitutional and interstitial Co, nanoholes as well as interstitial Mo, are responsible for the high magnetization.