First Principles Studies Of Transition-Metal Cluster Adsorptions On Penta-Garphene

Spintronics is an emerging discipline which uses the spin degree of electrons to realize the data storage and quantum computing.Spintronics materials including magnetic metals,topological insulators and magnetic semiconductors that possess the advantages of low power response,fast non-volatile and high memory density and thus have a wide range of applications,such as spin light-emitting diodes,spin electronic sensor,magnetic memory.With the increasing integration of electronic devices,the size of devices is required to be smaller,so new spintronic materials with thinner and smaller sizes are urgently needed.In addition,traditional spintronics is faced with problems such as the generation and injection of spin,long-range transmission of spin,control and detection of spin direction.Generally,there are two solutions to these problems.The first is based on the optimization and development of the device manufacturing process,and the second requires the artificial design of new spintronic materials.On the other hand,two-dimensional graphene has attracted tremendous attentions due to its excellent mechanical,electrical and optical properties.However,the zero-gap and non-magnetism nature of intrinsic graphene largely limits its further applications in semiconductor devices and spintronics.Therefore,to design two-dimensional magnetic systems with spin polarization by means of doping,adsorption and pressurization is of great significance for future low-dimensional spintronics devices.In this thesis,based on the first principle calculations,we systematically study the of deposition of transitional elements(TMs)(Fe,Ru,Os and Co,Rh,Ir)on Penta-Graphene(PG).Firstly,we construct possible adsorption configurations for the transition metal atoms and clusters on PG,and find out the most stable adsorption structure and explore the structural evolution through the calculation of adsorption energy,formation energy,superposition energy and binding energy.We discover that TM atoms prefer to adsorb at the bridge site and can be stably deposited on PG sheet.Secondly,the adsorbed transition metal atoms can effectively introduce the magnetic moment and simultaneously regulate the energy gap,which transforms the PG from being a wide-gap semiconductor to a narrow-gap semiconductor.It is worth noting that Ir5 cluster on PG exhibits half-metal behavior that can provide completely spin-polarization.Finally,the origin of magnetic anisotropy energy(MAE)is analyzed by fitting the second order perturbation model,and it is found that Os adatom presents the largest MAE of 113 meV.In conclusion,through systematic investigation of the electronic structure,magnetic moment distribution and MAE on transition metal adsorption on PG,we demonstrate that sizable magnetic moments and huge magnetic anisotropy as well as half-metal state can be induced.Moreover,we also reveal the origin of MAE via analysis of orbital-resolved density of state and second order perturbation model.These results show that the transition metal adsorption PG has rich and tunable electronic structure and magnetism that could provide great application potential in magnetic storage optical and spintronics devices.