First-principles Study On Co₂YX?X=P,As,Sb?

As a newly developed subject,spintronics has attracted more and more attention.Compared with the traditional semiconductor spintronic devices,spintronic devices use both the spin and the charge of the electron for the storage and processing of information,having advantages of high integration,low power consumption,etc.The key problem in the field of spintronics is to find the materials with high spin polarization and stable properties.So half-metal materials have attracted much attention due to their advantages,such as high spin polarization and high curie temperature and so on.Heusler alloy is a typical class of half-metal materials.The theory of the paper was the FLAPW(full potential linearized augmented plane wave)method which based on the DFT(density functional theory).The physical properties of Co2YX(X=P,As,Sb)with Heusler structure were studied by using the software WIEN2 k.Firstly,the structure of Heusler alloy was studied in detail based on the research background knowledge,and the modeling of Co2YX(X=P,As,Sb)with two different configurations was completed.Secondly,the structure optimization and total energy calculation were obtained for the nonmagnetic,ferromagnetic and antiferromagnetic states,found the more stable state and the optimal lattice constants.The two different configurations of Co2YX(X=P,As,Sb)were calculated by the crystal structure of the optimal lattice constants.The physical properties such as DOS(density of states),band structure,magnetic,elastic were analyzed.It was further verified whether they have the properties of half-metal materials.The mechanical stability was analyzed.and so were the optical properties of Co2YX(X=P,As,Sb)with Cu2 MnAl configuration.Eventually it was found that Co2YX(X=P,As,Sb)with Cu2 MnAl configuration are half-metal materials,and the spin polarization of Co2 YP and Co2 YSb is 100%.