| The physical properties of materials can be tuned by structural engineering,which can be realized in the experiment by applying pressure or strain and introducing impurities or vacancies,etc.It is in contrast with conventional three-dimensional materials,that the tunability of layered materials’ structure is perfect.In this paper,two-dimensional materials with α-PbO-type tetragonal lattice,such as layered FeSe and monolayer ZrN,were studied,and a high-throughput computational platform,which can create structures and calculate properties of materials,was constructed.We studied the effects of structural engineering on the properties of materials,such as electron-phonon coupling,dynamic stability and antiferromagnetism,as well.We explicitly study the two structural change factors,including the Wyckoff position of Se atom zSe and the lattice constants,in FeSe under the hydrostatic pressure individually to understand its influence on the electron-phonon coupling.We find that the increasing of the zse enhances the states around the Fermi level more,while the decreasing of the lattice constants enhances the phonon frequencies more,which together increase the electron-phonon coupling of FeSe under pressure.Based on the above facts,we predict and prove that the in-plane biaxial strain on FeSe increases the electron-phonon coupling due to the increasing zse and the decreasing in-plane lattice constant.This proves the feasibility of the structural engineering strategy of increasing the electron-phonon coupling of FeSe by increasing zSe and decreasing the lattice constant.There is a layer containing Zr and N atoms in the layered α-ZrNX(X=Cl,Br,I),which is extremely stable and similar to the layer of FeSe.According to structural engineering,we predict a new type of two-dimensional(2D)materials,called monolayer ZrN.From the results of the ab initio molecular dynamics(AIMD)simulation,this new type of 2D materials can be obtained by heating the monolayer ZrNI,which can be prepared by mechanical exfoliation method.It is proved that monolayer ZrN has the dynamic,thermal,and mechanical stability.There contains two zirconium(Zr)and two nitrogen(N)atoms in the unit cell of monolayer ZrN,and each atom is bonded to four neighboring atoms.The neighboring Zr atoms are antiferromagnetically coupled,and this coupling strong due to that the neighbor Zr distance in the buckled Zr-sublattice is small.The monolayer ZrN is a narrow-band gap antiferromagnetic semiconductor.By applying an external electric field on the monolayer ZrN,the spin current can be realized and controlled,and the antiferromanetic coupling remained stable.An abnormal in-plane negative Poisson’s ratio appears around the diagonal directions in the monolayer ZrN,and exhibit a better scalability than the monolayer MoS2 material.The antiferromagnetic coupling is weakened and the band gap increase by applying the uniaxial and biaxial compressive strain on the monolayer ZrN,while the monolayer ZrN becomes antiferromagnetic metal under the uniaxial and biaxial tensile strain.There is an anisotropic metastable state in monolayer ZrN,which is a non-magnetic metal and its electron-phonon coupling constant can reach 0.57,indicating its superconductivity.The results above have demonstrated great potential of monolayer ZrN in applications of nano-device.A huge number of comparable data are needed to study the influence of structural changes on material’s properties.The High-throughput Computational Platform is constructed in order to improve the efficiency of the structure predictions and property calculations in future.At present,this computational platform can create structures of binary random alloys,calculate the mechanical and thermodynamic properties.Besides,all the information will be collected and analyzed in this computational platform.We hope that the computational platform can be improved to study the influence of structural engineering on material’s properties,systematically and comprehensively. |
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