Magnetizing phosphorene via transition-metal doping: unveiling unconventional compensated magnetism

This study explores the magnetic and electronic properties of 3dtransition metal doped phosphorene monolayers using first principles calculations, with a focus on their potential two dimensional (2D) spintronics applications. We identify Ti, V, Cr, Mn and Fe doping induces magnetism in otherwise nonmagnetic phosphorene with respective magnetic moment of 1μ_B, 2μ_B, 3μ_B, 4μ_Band 3μ_Bper dopant. The induced magnetic moment is attributed to the intra-atomic charge transfer (from 4sto 3d) and subsequent spin-dependent electronic redistribution at the dopant site. Among the doped systems, Cr and Mn doped phosphorene exhibit ferromagnetic (FM) ground states with critical temperatures of 217.8 K and 733.5 K, respectively. On the other hand, Ti, V and Fe doping favor antiferromagnetic ordering with relatively lower critical temperatures, 147.1 K, 58.7 K and 52.2 K, respectively. While Ti and V doping retains semiconducting character with a band gap of 0.31 eV and 0.17 eV, respectively, the Cr, Mn and Fe doped systems are found to be metallic in nature. Notably, the Fe and V doped phosphorene monolayers exhibit unconventional compensated magnetism that combines the privilege of both ferromagnetism (spin-split band structure) and antiferromagnetism (zero net magnetization). While the former doped system is identified as a quasi-altermagnetic material, the latter one is predicted to be a Luttinger compensated magnetic semiconductor. Since they can facilitate an effective spin transport without any unwanted FM coupling, therefore, the Fe and V doped phosphorene monolayers are the preferred superior materials for applications in next-generation 2D spintronics.