First-Principles Study On The Physical Properties Of Yttrium-Silicon Metal Compounds

So far,rare earth-transition metal silicides are promising advanced technical materials.They have attracted great attention from researchers.With the development of science and technology,rare earth-transition metal silicides have attracted much attention in the development of ultra-large-scale integrated circuits,infrared detectors and other electronic devices due to their promising electrical properties.However,the inherent brittleness of materials hinders the industrial application of binary rare earth-transition metal silicides,and the research on ternary rare earth-transition metal compounds is not extensive.In order to further develop and use rare earth-transition metal silicides,the physical properties of ternary rare earth-transition metal compounds need to be elaborated.In this paper,the structural properties,mechanical properties,elastic anisotropy,electronic structure,optical properties and thermodynamic properties of eleven tetragonal rare earth-transition metal silicides TM₂Si₂Y（TM=Cu,Ir,Os,Pd,Pt,Rh,Ru,Cr,Fe,Co and Ni）were studied by first-principles calculations.In addition,the effects of substitution and doping of transition metal atoms on the physical properties of hexagonal Si₃Y₅were studied.The results show that the ternary TM₂Si₂Y silicide exhibits structural stability according to the lattice vibration data and thermodynamic parameters.TM₂Si₂Y（TM=Os,Pd,Pt,Rh,Ru and Ni）conforms to the ductile behavior condition.Optical properties suggest that TM₂Si₂Y exhibits good photoconductivity.The thermodynamic parameters show that TM₂Si₂Y is thermodynamically stable at high temperature.Different atom substitution and doping Si₃Y₅models are structurally stable.The substitution and doping of transition metal atoms weaken the hardness of Si₃Y₅,but improve its brittleness.In particular,the presence of Mo and W atoms makes Si₃Y₅a ductile material.Combined with the calculated electronic structure,the Si₃Y₅silicides with different atom substitution and doping can be explained.