High-throughput Calculation Of The Spin Transport And Band Gap Properties In Heusler Compounds

With the development of the integrated circuit,chips are gradually developing towards low energy consumption and integration.However,as the conventional CMOS scaling has now approached the fundamental limits,Moore's law will cease to apply.In order to move past the era of Moore's law,breakthroughs are needed in the intergraded circuit industry.Compared with traditional CMOS transistors that are based on the fundamental electronic charge,spintronic devices that use spins and magnets for information processing have become new hopes for researchers to further expand the computing capabilities of chips.Heusler compounds are perhaps some of the most attractive compounds for researchers to study future applications in spintronics devices.It has been shown that the compounds can be stable with various combinations of X,Y,and Z elements leading to a tremendous variety of properties attached to them:half metallicity,Weyl topological material,thermoelectricity,and infrared radiation application.In this thesis,the transport properties such as spin Hall conductivity,anomalous Hall conductivity,and anomalous Nernst conductivity in about 120 full Heusler compounds are calculated using the density functional theory in a high-throughput way.In addition,high-throughput calculations are also used to screen the band gaps of half-Heusler materials with different exchange-energy functionals,and the tunneling of band gaps in half-Heusler compounds was discussed.We first study the spin Hall conductivity and anomalous Hall conductivity of 120full Heusler compounds.Our results show that the spin Hall conductivity and anomalous Hall conductivity cannot be simply related to the valence electron numbers or atomic weights,but also more related to the topology of electronic band structures,thus the high-throughput calculation is the most efficient way to study Hall conductivity.According to our results,full Heusler compounds such as Rh₂Mn Al(729(?)/0)^-1(88)^-1),Cu₂Co Sn(578(?)/0)^-1(88)^-1)are promising candidates in spintronic devices like Co₂Mn Al(649(?)/0)^-1(88)^-1)and Co₂Mn Ga(633(?)/0)^-1(88)^-1),which have been reported before regarding their high spin Hall conductivity and anomalous Hall values.We also studied the anomalous Nernst conductivity of full Heusler compounds in this thesis.According to our results,full Heusler compounds such as Rh₂Sn Ni(7.478)^-1-1),Cu₂Fe Sn(4.358)^-1-1),Rh₂Mn Al(2.758)^-1-1)are promising candidates in thermoelectric devices.Finally,high-throughput calculations of the band gaps in all half-Heusler materials are performed by m BJ and SCAN functionals.We gained some materials such as Pr Bi Pd that could be used as infrared materials.We also noticed that the topological insulator property of some half Heusler compounds is similar to Hg Te,which is a well-known infrared material.Here we present the tunneling of band gap for doped La Pd_1-xPt_xBi,which could be used as a promising infrared material.