First-Principle Study On The Electronic Structure And Magnetic Properties Of Sm （Co, M）₅

The development of information storage technology requires the hard disk drive （HDD）with greater capacity and higher areal recording density. Therefore, it is imperative that thematerials possessing strong magnetic anisotropy in nature are used in magnetic recordingmedia. As the representative of rare earth-transition metal （R-T） compounds with stronguniaxial magnetic anisotropy Ku, high saturation magnetization MSand high Curietemperature TC, SmCo₅has become the new candidates for ultra-high density perpendicularmagnetic recording media, which have attracted great interest both from experiment andtheoretical researchers.In recent years, the use of first principles calculations for magnetic anisotropy energy（MAE） of magnetic materials has been widespread concern. In this paper, the densityfunctional theory （DFT） with the pseudopotential plane wave DFT code Vienna ab initiosimulation package （VASP） with the projector augmented wave （PAW） method in MedeAsoftware is used to simulate the electronic structure and the magnetic properties of SmCo₅.The local density approximation LDA+U method including spin-orbit coupling （SOC） isused for the calculation of the exchange correlation energy of SmCo₅. The origin of highmagnetic anisotropy of SmCo₅is analyzed. On this basis, further study of the magneticmetals Fe doping and non-magnetic metals Cu doping effects of the magnetic properties ofSm（Co, M）₅was considered.The electronic density of states and the differential in spin densities of atoms show thatthe spatial distribution of4f electron and the4f–3d coupling are the controlling factors ofthe magnetic anisotropy energy of SmCo₅.The calculations including spin-orbit coupling（SOC） show that the magnetic moment of Co atoms is mainly provided by the spinmagnetic moment, while the orbital magnetic moment is very weak. The spin and orbitalmagnetic moment of Sm atom are in the opposite direction, which brings about the smalltotal magnetic moment of Sm. The MAE of SmCo₅mainly comes from the crystal fieldeffect and spin-orbit coupling effect. The investigation of the magnetic properties of Sm（Co,M）₅shows that the doping effects of magnetic element Fe and non-magnetic element Cuare quite different. It is expected that the Sm（Co1-xCux）₅alloys with x=0-0.2and the Sm（Co1-xFex）₅alloys with x=0.6-0.8could be good candidates for hard magnet andmagnetic recording media.