Magnetic Properties Of Rare Earth Pr³⁺ ,Ho³⁺ Doped CuS Based Diluted Magnetic Semiconductor

Diluted magnetic semiconductor has both magnetic properties and semiconductor properties.At the same time,it makes use of two degrees of freedom of electron,namely electron spin and charge.On this basis,spintronics,which combines magnetism and microelectronics,is developed.Spintronic devices are compared with traditional microelectronics devices.They have the advantages of low energy consumption,fast operation speed,non-volatile and high integration density,which are of great value in the practical application fields.Doping is an effective method for preparing diluted magnetic semiconductors,which can satisfy the practical application of spintronic devices.CuS nanoparticles were used as the main material,and rare earth elements Pr and Ho were doped.Magnetic tests were carried out on the samples,and the source of their magnetism was analyzed.Finally,the magnetic mechanism of the samples was calculated and analyzed by first principles.The main research results of this paper are as follows:1.CuS:Pr³⁺and CuS:Ho³⁺nanoparticles with different doping concentrations were prepared by aerosol condensation chemical deposition method.Structure analysis showed that rare earth ions Pr³⁺and Ho³⁺occupied the positions of Cu ions in CuS lattice,and the rare earth ions were successfully incorporated into CuS lattice.The grain sizes are about 7.9 nm,8.5 nm and 9 nm,respectively.2.Magnetic tests showed that the maximum saturated magnetization(M_s)of CuS:Pr³⁺and CuS:Ho³⁺nanoparticles at room temperature was respectively 0.00298emu g^-1 and 0.00443 emu g^-1.The results show room temperature ferromagnetism.With the increase of doping concentration,M_s value increases first and then decreases.CuS based thin magnetic semiconductor with room temperature ferromagnetism was successfully prepared.3.The source of room-temperature ferromagnetism is explained by first-principles state density calculation and bound magnetic polaron model.The ferromagnetism of Pr³⁺doping system mainly comes from the contribution of Cu 3d,S 3s,S 3p and Pr 4f orbital electrons except Pr 4f_xyz.The ferromagnetism of Ho³⁺doped system mainly comes from the spin splitting of the Ho 4f orbital.The more bound magnetic polaron clusters formed,the greater the ferromagnetism.The distance between magnetic ions is shortened,antiferromagnetic coupling occurs,and ferromagnetism is weakened.