Theoretical Study On Structure,stability,magnetic And Electronic Properties Of V_n@Si₁₂ Cluster Assembled Nanowires

Due to the rapid development of cluster science,cluster assembly provides exciting prospects in the field of nanoscale science.Through selecting stable clusters as building blocks and using the"bottom-up"approach,cluster assembly can be used to"engineer"the materials properties as desired.Therefore,cluster assembly is considered to be one of the most promising and effective ways to design and develop new functional materials.People use silicon-based clusters to assemble a variety of one-dimensional?1D?nanowires/nanotubes and two-dimensional?2D?crystal materials.Based on this,we designed a series of one dimensional nanowires?NWs?assembled by V₁@Si₁₂clusters,and their structures,stabilities,magnetic and electronic properties were examined by means of density functional theory computations.We found that 1D V₁@Si₁₂-NW-rI along the radial direction of the Si₁₂ drum exhibits good stabilities,antiferromagnetism and tunable electronic behavior under external strains.However,the NWs built along the axial direction of the Si₁₂ drum are not dynamically stable.Meanwhile,our study also found that Si₁₂2 containing other TM(Ti₁@Si₁₂)and more V atoms(V₃@Si₁₂)could be assembled into stable 1D NWs in the radial direction of the Si₁₂ drum,and the magnetic and electronic characters could be tuned through external strains.The assembled V₃@Si₁₂ nanowires will not change the ferromagnetic configuration in the V₃@Si₁₂ unit.The 1D V₃@Si₁₂-NW-a is an indirect-bandgap semiconductor,whose bandgap is 0.71 eV,while the 1D V₃@Si₁₂-NW-r is a direct-bandgap semiconductor,and the bandgaps of the two spin channels are 0.44 and 0.76 eV,respectively,the compression can convert the semiconductor to a half-metal or a metal,the tensile strain can tune the gap values of the two spin channels;The 1D Ti₁@Si₁₂-NW-r with the same structure to the 1D V₁@Si₁₂-NW-rI is a nonmagnetic semiconductor whose direct-bandgap is 0.10 eV.Our theoretical research provide a new assembling way to design one dimensional nanowires with novel structural and diverse magnetic and electronic properties.