Transition Metal Clusters Based Materials And Their Interaction With Molecules: A First-principles Investigation

With the continuous development and progress of science and technology,the research about low dimensional materials has been paid more and more attention.Among them,clusters have extensive applications due to their unique structure and characteristics.In addition,a class of structural units with unique structural,optical,magnetic and thermodynamic properties can be designed and constructed from small-sized clusters,it plays a certain role in promoting modern nanoscience.So we will think what role do zero dimensional clusters play in different dimensions?In this paper,based on the first-principles calculations of density functional theory,the mixed cluster is selected as the research object,and the following three aspects are studied:(1)The adsorption behaviors of seven molecules(CO,CO₂,N₂,NO,O₂,N₂O and NO₂)on Rh₃X(X=Sc-Zn,Y-Cd)clusters are systematically investigated.A strong correlation was found between adsorption behavior and molecular types.Besides,Adsorption energies show the different boundaries.these results indicate that the doped rhodium clusters can be viewed as good candidates in the discrimination between different gas molecules.(2)The stability and electronic properties of Cd₁₂O₁₂ cluster-assembled nanowires and Na-doped Cd₁₂O₁₂nanowire are studied.The results show that both Cd₁₂O₁₂ nanowire and Na-doped Cd₁₂O₁₂nanowire are thermodynamically stable(at least at room temperature).The most stable nanowire exhibits semiconducting properties with a direct energy gap.After doping Na atoms into the nanowire,the electronic properties of the Cd₁₂O₁₂-based nanowire present dramatic changes,and the system transforms from semiconducting to metallic.It can provide a theoretical guidance for the potential application of Cd₁₂O₁₂-based semiconductor devices.(3)The geometrical structure,electronic structure and magnetic properties of 3d-transition metal(Sc,Ti,Cr,Mn,Co,Cu and Zn)doped Cd₁₂O₁₂ nanowires are systematically investigated.The results show that all the doping systems are thermodynamically stable.The system retains the original characteristics of non-magnetic semiconductor with doping Ti or Zn.When Mn,CO or Cu is doped,the magnetic semiconducting state can be realized.While when Sc(Cr)is doped,the system changes to non-magnetic metallic state(magnetic metallic state).The results show that the Cd₁₂O₁₂nanowires doped with 3d transition metal elements have potential applications in the fields of electronics,optoelectronics and spintronics.