Study Of The Tunable Conductive And Magnetic Properties In The Doped Two Dimensional Platinum Diselinide

Dimensionality plays a vital role in determining the characteristics of materials.After the most studied graphene,recently the researchers have been putting remarkable efforts to discover other 2D materials with interesting properties.For instance,transition metal dichalcogenide monolayers have attracted great interests because of their exceptional properties,which are quite beneficial for some potential applications e.g.integrated circuits,transparent conducting electrodes,photoluminescence and valleytronics.Since most of the existing pristine 2D materials exhibit nonmagnetic properties,one of the scientific concerns in this regard is whether TMDCs can possess desirable magnetic behaviour.Recent researches have revealed that 2D TMDCs undergoes unusual changes in their physical properties when subjected to strain,chemical functionalization,doping with transition metals,and external electric fields.Additionally,large DOS at or near the Fermi energy of a system would lead to instabilities and transitions to different phases such as ferro/antiferromagnetic half metallicity,superconductivity,and other phenomena.Thus,the magnetic properties of the doped and stretched 1T-PtSe₂monolayer are likely to be dissimilar from its pristine form.On basis of the first-principles calculations,we have studied the effects of hole doping and biaxial tensile strain on the electronic and magnetic properties of monolayer of platinum diselenide?PtSe₂?.Due to the large density of states near the valence band edge,this nonmagnetic monolayer semiconductor switches to a ferromagnetic half metal within a small range of hole doping.With an increase of hole density,average magnetic moment per carrier also increases and reaches at its maximum value over a specific range of carrier density while the system remains in a half metal state before the magnetic moment abruptly begins to fall.We also predict a critical value of biaxial tensile strain?5%?for doped monolayer PtSe₂,after which the optimal carrier density becomes constant while the magnetic moment/carrier gradually increases and the ferromagnetic state of the system becomes more stable with increasing values of strain.Chemically modified PtSe₂monolayers exhibit some fascinating electronic and mag-netic features,which originate from hybridization between the dopants and nearest local atoms.Exceptional electronic and magnetic characters are observed in the B-,P-,Li-,and Ca-doped cases because of doping site independence.The magnetic behavior of the dopant atoms is found to be complex because of interplay between strong structural relaxation,spin lattice coupling,and crystal field splitting.More interestingly,the fer-romagnetic half metallic character obtained in B-and N-doped cases,expected to be very useful because of large half metallic energy bandgap.The long range ferromagnetic behavior can be found for the B-,F-,N-,P-,and Li-doped at Pt sites,which suggest the high magnetic transition temperatures.We have also predicted a strong antiferromagnetic half metallicity that can easily be achieved from the semi nitrogenation of the PtSe₂monolayer as a result of unusual spin splittings.Such surface functionalization induces a high magnetic moment of 4?_Bper unit cell.Significantly,a reasonable half-metallic bandgap of 0.4 eV has also been obtained along the high estimated Neèl temperature of 724 K,which suggests the possibility of practical implementation of such a stable antiferromagnetic half-metallicity even at high temperature.Additionally,the calculated formation energies and kinetic analysis confirms their experimental feasibility.These works unveiled some of the possibilities which are necessary require to engineer the unexplored intruding magnetic characteristics of the low dimensional nano-structures especially PtSe₂monolayer.