Cr_(1-x)Nb_xSi_2固溶体弹性性质、电子结构和光学性质的第一性能计算
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摘要
采用基于密度泛函理论(DFT)的第一性原理计算,对Nb掺杂CrSi_2的晶格结构、弹性性质,电子结构和光学性质进行了系统的研究.研究结果表明:随着Nb掺杂浓度增加,弹性常数、体变模量、剪切模量、杨氏模量均减小,而且能带间隙也逐渐减小,表现为p型掺杂特点.基于电子结构计算结果以及已知的实验结果,讨论了Nb掺杂CrSi_2后对其复介电函数、折射率、消光系数、反射率和吸收谱等光学性质的影响.
The structures,elastic,electronic and optical properties of Nb doped CrSi_2 are calculated by first principle method based on density function theory. Present results indicate that the elastic constants,bulk,shear,Young's moduli and band gap are decreased with the increasing concentration of Nb. The band structure indicates p-type semiconductor characteristic for Nb doped CrSi_2. The projected densities of states are calculated to analyze the orbital hybridized behaviors of the Cr_(1-x)Nb_xSi_2 solid solutions. Furthermore,we calculate the complex dielectric functions on account of electronic properties. The optical properties,including refractive index,extinction coefficient,reflectivity and absorption spectrum,are calculated by Kramers-Kronig transformation according to the dielectric functions. The optical properties of CrSi_2 are in good agreement with the theoretical and experimental results,and the effects of Nb doping on the optical properties of CrSi_2 are discussed.
The structures,elastic,electronic and optical properties of Nb doped CrSi_2 are calculated by first principle method based on density function theory. Present results indicate that the elastic constants,bulk,shear,Young's moduli and band gap are decreased with the increasing concentration of Nb. The band structure indicates p-type semiconductor characteristic for Nb doped CrSi_2. The projected densities of states are calculated to analyze the orbital hybridized behaviors of the Cr_(1-x)Nb_xSi_2 solid solutions. Furthermore,we calculate the complex dielectric functions on account of electronic properties. The optical properties,including refractive index,extinction coefficient,reflectivity and absorption spectrum,are calculated by Kramers-Kronig transformation according to the dielectric functions. The optical properties of CrSi_2 are in good agreement with the theoretical and experimental results,and the effects of Nb doping on the optical properties of CrSi_2 are discussed.
引文
[1]Nicolet M A,Lau S S.Formation and characterization of transition-metal silicides[J].Vlsi Electronics Microstructure Science,1983,6:329.
[2]Bost M C,Mahan J E.An investigation of the optical constants and band gap of chromium disilicide[J].J.Appl.Phys.,1988,63:839.
[3]Bellani V,Guizzetti G,Marabelli F,et al.Theory and experiment on the optical properties of Cr Si2[J].Phys.Rev.B,1992,46:9380.
[4]Lange H.Electronic properties of semiconducting silicides[J].Phys.Stat.Soli.B,1997,201:3.
[5]Pan Z J,Zhang L T,Wu J S.Effects of Al doping on the transport performances of Cr Si2single crystals[J].Scr.Mater.,2007,56:245.
[6]Pan Z J,Zhang L T,Wu J S.Effects of V doping on the transport performances of Cr Si2single crystals[J].Scr.Mater.,2007,56:257.
[7]Karuppaiah S,Beaudhuin M,Viennois R.Investigation on the thermoelectric properties of nanostructured Cr11-xTixSi2[J].J.Solid State Chem.,2013,199:90.
[8]Ohishi Y,Mohamad A,Miyazaki Y,et al.Thermoelectric properties of Cr1-xMoxSi2[J].J.Phys.Chem.Solids,2015,87:153.
[9]Hermet P,Khalil M,Viennois R,et al.Revisited phonon assignment and electro-mechanical properties of chromium disilicide[J].RSC Adv.,2015,5:19106.
[10]Nakamura M.Elastic constants of some transitionmetal-disilicide single crystals[J].Metal.Mater.Trans.A,1994,25:331.
[11]Nagai H,Takamatsu T,Iijima Y,et al.Effects of Nb substitution on thermoelectric properties of Cr Si2[J].J.Alloy.Compd.,2016,687:37.
[12]Segall M D,Lindan P J D,Probert M J,et al.Firstprinciples simulation:ideas,illustrations and the CASTEPcode[J].J.Phys.:Condens.Matt.,2002,14:2717.
[13]Khalil M,Beaudhuin M,Villeroy B,et al.A modeling approach for new Cr Si2based alloys:Application to metastable Cr1-xZrxSi2as a potential thermoelectric material[J].J.Alloy.Compd.,2016,662:150.
[14]Pugh S F.Relations between the elastic moduli and the plastic properties of polycrystalline pure metals[J],Philos.Mag.,1954,45:823.
[15]Cui S X,Wei D W,Hu H Q,et al,First-principles study of the structural and elastic properties of Cr2Al X(X=N,C)compounds[J].J.Solid State Chem.,2012,191:147.
[16]Anderson O L,A simplified method for calculating the Debye temperature from elastic constants[J].J.Phys.Chem.Solids,1963,24:909.
[17]Poirier J P.Introduction of the physics of earth interior[M].2000:498.
[18]Anderson O L.A simplified method for calculating the Debye temperature from elastic constants[J].J.Phys.Chem.Solids,1963,24:909.
[19]Zhang Z Z,Zhang C H,YAN W J,et al.First principle study on electronic structure and optical properties of Cr Si2doped rare earth element La[J].J.At.Mol.Phys.,2014,31:652(in Chinese)[张忠政,张春红,闫万珺,等.稀土La掺杂Cr Si2电子结构与光学性质的第一性原理研究[J].原子与分子物理学报,2014,31:652]
[20]Yan W J,Zhang C H,Zhou S Y,et al.First principle calculation of optical-electrical characteristics of Ti doped Cr Si2[J].J.At.Mol.Phys.,2014,31:167(in Chinese)[闫万珺,张春红,周士芸,等.第一性原理计算Ti掺杂Cr Si2的光电特性[J].原子与分子物理学报,2014,31:167]
[21]Nava F,Tu K N,Thomas O,et al.Electrical and optical properties of silicide single crystals and thin films[J].Mater.Sci.Rep.,1993,9:141.
[22]Yu P Y,Cardona M,Sham L J.Fundamentals of semiconductors:physics and materials properties[J].Semicond.Sci.Technol.,2008,50:76.
[2]Bost M C,Mahan J E.An investigation of the optical constants and band gap of chromium disilicide[J].J.Appl.Phys.,1988,63:839.
[3]Bellani V,Guizzetti G,Marabelli F,et al.Theory and experiment on the optical properties of Cr Si2[J].Phys.Rev.B,1992,46:9380.
[4]Lange H.Electronic properties of semiconducting silicides[J].Phys.Stat.Soli.B,1997,201:3.
[5]Pan Z J,Zhang L T,Wu J S.Effects of Al doping on the transport performances of Cr Si2single crystals[J].Scr.Mater.,2007,56:245.
[6]Pan Z J,Zhang L T,Wu J S.Effects of V doping on the transport performances of Cr Si2single crystals[J].Scr.Mater.,2007,56:257.
[7]Karuppaiah S,Beaudhuin M,Viennois R.Investigation on the thermoelectric properties of nanostructured Cr11-xTixSi2[J].J.Solid State Chem.,2013,199:90.
[8]Ohishi Y,Mohamad A,Miyazaki Y,et al.Thermoelectric properties of Cr1-xMoxSi2[J].J.Phys.Chem.Solids,2015,87:153.
[9]Hermet P,Khalil M,Viennois R,et al.Revisited phonon assignment and electro-mechanical properties of chromium disilicide[J].RSC Adv.,2015,5:19106.
[10]Nakamura M.Elastic constants of some transitionmetal-disilicide single crystals[J].Metal.Mater.Trans.A,1994,25:331.
[11]Nagai H,Takamatsu T,Iijima Y,et al.Effects of Nb substitution on thermoelectric properties of Cr Si2[J].J.Alloy.Compd.,2016,687:37.
[12]Segall M D,Lindan P J D,Probert M J,et al.Firstprinciples simulation:ideas,illustrations and the CASTEPcode[J].J.Phys.:Condens.Matt.,2002,14:2717.
[13]Khalil M,Beaudhuin M,Villeroy B,et al.A modeling approach for new Cr Si2based alloys:Application to metastable Cr1-xZrxSi2as a potential thermoelectric material[J].J.Alloy.Compd.,2016,662:150.
[14]Pugh S F.Relations between the elastic moduli and the plastic properties of polycrystalline pure metals[J],Philos.Mag.,1954,45:823.
[15]Cui S X,Wei D W,Hu H Q,et al,First-principles study of the structural and elastic properties of Cr2Al X(X=N,C)compounds[J].J.Solid State Chem.,2012,191:147.
[16]Anderson O L,A simplified method for calculating the Debye temperature from elastic constants[J].J.Phys.Chem.Solids,1963,24:909.
[17]Poirier J P.Introduction of the physics of earth interior[M].2000:498.
[18]Anderson O L.A simplified method for calculating the Debye temperature from elastic constants[J].J.Phys.Chem.Solids,1963,24:909.
[19]Zhang Z Z,Zhang C H,YAN W J,et al.First principle study on electronic structure and optical properties of Cr Si2doped rare earth element La[J].J.At.Mol.Phys.,2014,31:652(in Chinese)[张忠政,张春红,闫万珺,等.稀土La掺杂Cr Si2电子结构与光学性质的第一性原理研究[J].原子与分子物理学报,2014,31:652]
[20]Yan W J,Zhang C H,Zhou S Y,et al.First principle calculation of optical-electrical characteristics of Ti doped Cr Si2[J].J.At.Mol.Phys.,2014,31:167(in Chinese)[闫万珺,张春红,周士芸,等.第一性原理计算Ti掺杂Cr Si2的光电特性[J].原子与分子物理学报,2014,31:167]
[21]Nava F,Tu K N,Thomas O,et al.Electrical and optical properties of silicide single crystals and thin films[J].Mater.Sci.Rep.,1993,9:141.
[22]Yu P Y,Cardona M,Sham L J.Fundamentals of semiconductors:physics and materials properties[J].Semicond.Sci.Technol.,2008,50:76.