Resarch On The Magnetic Properties Of ?-(Zn,Cr)S

With the development of the times,radio technology has become an important pillar of the modern information society.The research on magnetism has been promoted under the demand of radio technology,and spintronics has been produced;in turn,research from spintronics will certainly be backed up in radio technology in the future.In this thesis,with first principle calculations,the increasement of magnetic exchange energy?MEE?of two-dimensional?2d?diluted magnetic semiconductor?DMS??–?Zn,Cr?S with shape deformation was studied.The shape deformation that increase the lattice parameter perpendicular to the Cr layer or decrease the lattice parameter parallel to Cr layer could increase MEE of the system obviously.The main mechanism is Zener's double exchange?DE?,in which,shape deformation could vary the hole states and make Fermi level site at middle of the hole.This enriches the research of 2d FM materials.Based on the first work,we continiue calculated the atomic structure and electronic structure of the heterojunction?-?Zn,Cr?S?111?,where one Cr layer lied on the ZnS?111?surface.Cr layer on surface breaks the spatial inversion symmetry and results in the chiral Dzyaloshinsky-Moriya interaction?DMI?.Magnetic interaction between Cr atoms is through the nearest layer of S atoms.Combined with the generalized Bloch condition,the dispersion relationship E?q?and E?-q?between the spin spiral energy and the wave vector in the opposite direction is calculated.The energy difference between E?q?and E?-q?reflects the magnitude of DMI between the S layer and the Cr layer of?-?Zn,Cr?S?111?.By fitting the first-principles calculations with the Heisenberg interaction?HBI?model and the DMI model,the HBI parameters J₁-J₄ and DMI parameters d₁,d₂ of the neighbors between Cr atoms are obtained.In?-?Zn,Cr?S?111?,the coupling between Cr atoms is M-type antiferromagnetic.The DMI parameter d1 is-0.53 meV,which is a clockwise chiral DMI,and a skyrmion may be produced at the?-?Zn,Cr?S?111?interface.The calculations in this paper indicate that DMI may exist in magnetic and non-magnetic semiconductor interfaces,opening up a new direction for theoretical research and advances in magnetic storage technology.