Using first-principle calculations, we investigate the mechanical, structural, and electronic properties and formation energy of 25 kinds of Ⅲ–V binary monolayers in detail. A relative radius of the binary compound ...Using first-principle calculations, we investigate the mechanical, structural, and electronic properties and formation energy of 25 kinds of Ⅲ–V binary monolayers in detail. A relative radius of the binary compound according to the atomic number in the periodic table is defined, and based on the definition, the 25 kinds of Ⅲ–V binary compounds are exactly located at a symmetric position in a symmetric matrix. The mechanical properties and band gaps are found to be very dependent on relative radius, while the effective mass of holes and electrons are found to be less dependent. A linear function between Young’s modulus and formation energy is fitted with a linear relation in this paper. The change regularity of physical properties of B–V(V = P, As, Sb, Bi) and Ⅲ–N(Ⅲ = Al, Ga, In, Tl) are found to be very different from those of other Ⅲ–V binary compounds.展开更多
Complex VO(C\-\{12\}H\-\{12\}N\-2O\-2)(C\-\{13\}H\-\{10\}NO\-2)(C\-\{12\}H\-\{12\}N\-2O\+\{\{\}\+\{2-\}\}\-2=acetylacetone benzoylhydrozanate,C\-\{13\}H\-\{10\}NO\+_\-2=\%N\%\|phenylbenzohydroxamate) was synthesized a...Complex VO(C\-\{12\}H\-\{12\}N\-2O\-2)(C\-\{13\}H\-\{10\}NO\-2)(C\-\{12\}H\-\{12\}N\-2O\+\{\{\}\+\{2-\}\}\-2=acetylacetone benzoylhydrozanate,C\-\{13\}H\-\{10\}NO\+_\-2=\%N\%\|phenylbenzohydroxamate) was synthesized and characterized by means of elemental analysis,IR and UV spectroscopies,cyclic voltammetry and single crystal X\|ray diffraction. The complex crystallized in the monoclinic system with space group \%P\%2\-1/\%n\% and the crystal cell parameters \%a\%=1\^3003(1) nm,\%b\%=0\^88836(6) nm,\%c\%=2\^0196(2) nm,\%β\%=95\^065(8)°,\%V\%=2\^3238(3) nm\+3,\%M\%\-r=495\^40 and \%Z\%=4. The two oxygen and one nitrogen atoms of the tridentate hydrazone ligand coordinate to the vanadium atom,forming an equatorial plane. And the coordinated vanadium atom exhibits a distorted octahedral geometry. The atom in the transposition to the oxo O atom is the carbonyl oxygen atom of the hydroxamate ligand in the complex. The half\|wave redox potential of the title complex in the three different solvents positively shifts in the order of CH\-2Cl\-2<CH\-3CN<DMF.展开更多
The crystal structure of the title compound, [enH2][Fe{MoⅤ6O12(OH)3(HPO4)- (H2PO4)3}2]6en6H2O (en = H2NCH2CH2NH2), hydrothermally synthesized from a mixture of Na2MoO42H2O, Fe2(SO4)3, H3PO4, H2N(CH2)2NH2 and water, h...The crystal structure of the title compound, [enH2][Fe{MoⅤ6O12(OH)3(HPO4)- (H2PO4)3}2]6en6H2O (en = H2NCH2CH2NH2), hydrothermally synthesized from a mixture of Na2MoO42H2O, Fe2(SO4)3, H3PO4, H2N(CH2)2NH2 and water, has been determined by single- crystal X-ray diffraction. The crystal is of triclinic, space group P?with a = 11.9014(1), b = 13.4246(2), c = 13.8719(2) , a = 87.465(1), b = 69.981(1), g = 64.960(1)? V = 1873.46(4) 3, Z = 1, Mr = 2997.89, F(000) = 1466, m = 2.427 mm-1 and Dc = 2.657 g/cm3. The final R = 0.0404 for 5570 observed reflections (I > 2s(I)). The structural analysis reveals that each cluster anion contains two coplanar {Mo6} rings of six edge-sharing Mo(O5OH) octahedra, and the two {Mo6} rings are linked together through one octahedral FeⅡ ion to generate a sandwich-type cluster with rigorous () symmetry. Moreover, these clusters are further linked into a three-dimensional frame- work by hydrogen bonds.展开更多
etra ( N, N-diethyldithiocarbamates ) Samarium (Ⅲ)tetra (N, N-di-ethyldithiocarbamates) Molybdenum (V)([Mo (dtc)][Sm (dtc)])was synthesizedby the reaction of [Mo(dtc)]Cl and Na[Sm(dtc)] in miethanol. The crystal stru...etra ( N, N-diethyldithiocarbamates ) Samarium (Ⅲ)tetra (N, N-di-ethyldithiocarbamates) Molybdenum (V)([Mo (dtc)][Sm (dtc)])was synthesizedby the reaction of [Mo(dtc)]Cl and Na[Sm(dtc)] in miethanol. The crystal struc-ture was determined using X-ray diffraction methods. The compound crystallizes inthe triclinic space group P1 with the lattice parameters: a =1. 1557(4) nm, b=1.5253(3) nm, c=1. 8670 (6) nm and a=97.001 (20)°, β=94. 506(24)°, γ=93. 419(20)°,Z=2.The final R=0.059.The spectroscopic and XPS studies werecarried out.展开更多
介绍以高能紫外激光为光源的、研究 MIS 结构电荷特性的光Ⅰ-Ⅴ法。简述了该法实验原理、实验装置和测试方法;给出了由传统热氧化的 SiO_2介质膜和新型快速热氮化的 SiOxNy 膜(缩写为 RTNF)组成的 MIS 结构的光Ⅰ-Ⅴ实验数据、体电荷密...介绍以高能紫外激光为光源的、研究 MIS 结构电荷特性的光Ⅰ-Ⅴ法。简述了该法实验原理、实验装置和测试方法;给出了由传统热氧化的 SiO_2介质膜和新型快速热氮化的 SiOxNy 膜(缩写为 RTNF)组成的 MIS 结构的光Ⅰ-Ⅴ实验数据、体电荷密度和平均分布中心的实验结果。并就该法优缺点、应用前景及改进途径作了讨论.展开更多
Divanadium（Ⅴ） complex [VO（aptch）（μ-OCH3）]2（1） and two monovanadium（Ⅴ） complexes [VO（apfah））（OEt）]（2a and 2b,H2aptch = 2-hydroxyacetophenone thiophene-2-car-boxylic hydrazone,H2apfah = 2-hydroxyaceto...Divanadium（Ⅴ） complex [VO（aptch）（μ-OCH3）]2（1） and two monovanadium（Ⅴ） complexes [VO（apfah））（OEt）]（2a and 2b,H2aptch = 2-hydroxyacetophenone thiophene-2-car-boxylic hydrazone,H2apfah = 2-hydroxyacetophenone 2-furoic acid hydrazone） have been synthesized and characterized.Single-crystal X-ray diffraction studies reveal that 1 is a cen-trosymmetric dimer bridged by two methoxido O-atoms.Complex 1 crystallizes in the monoclinic crystal system,space groups P21/c with a = 7.4825（4）,b = 17.0928（11）,c = 11.6961（7） ,β = 98.172（4）o,Z = 2,F（000） = 728,μ = 0.829 mm-1,the final R = 0.0457 and wR = 0.1137 for 2654 observed reflections with I 〉 2（I）.The vanadium（V） is coordinated to the tridentate ligand,ethanol molecule to form a distorted square-pyramidal geometry,complexes 2a and 2b.Although 2a and 2b have the same asymmetric unit,they belong to different space groups.Complex 2a crystallizes in the monoclinic crystal system,space groups P21/n with a = 10.2293（2）,b = 15.6660（3）,c = 10.6298（2） ,β = 116.259（1）o,Z = 4,μ = 0.676 mm-1;complex 2b crystallizes in the triclinic crystal system,space groups P with a = 8.2808（4）,b = 9.4704（5）,c = 10.0819（5） ,α = 86.133（3）,= 81.956（3）,γ = 80.248（3）o,Z = 2 and μ = 0.670 mm-1.The hydrogen bonds are found to exist in 2b only.The crystal structure is stabilized by intermolecular hydrogen bonds of C-H···O.展开更多
The development of new materials,having exceptional properties in comparison to existing materials is highly required for bringing advancement in electronic and optoelectronic technologies.Keeping this fact,we investi...The development of new materials,having exceptional properties in comparison to existing materials is highly required for bringing advancement in electronic and optoelectronic technologies.Keeping this fact,we investigated structural,electronic,and optical properties of zincblende GaN doped with selected Zn concentrations(6.25%,12.50%,and 18.70%),using the first-principle calculations based on density functional theory with GGA+U.We conducted the entire study using the WIEN2K code.In this study,we calculated various significant parametric quantities such as cohesive energies,formation energies,bulk moduli,and lattice constants along with the study of optical and electronic properties by substituting Ga atoms with Zn atoms in 1×2×2 supercell.The structural stability is confirmed by studying the phonon dispersion curves which suggest that Zn:GaN material is stable against the 6.25%and 18.70%Zn concentrations while for 12.50%,it shows instability.The Hubbard values U=0,2,4,6 eV were added to GGA and the electronic properties were improved with the U=6 eV.Optical absorption was blue shifted while the refractive index and dielectric constant were increased with increasing the Zn concentrations.Electronic properties are enhanced due to the prime contribution of cations(Zn)3ri states.The optical and electronic properties are further discussed in detail in the entire study.展开更多
Advantages of the detached phenomena have influenced researchers to modify the conventional methods to promote it on the earth. Since 1994, the vertical directional solidification （VDS） technique has been employed f...Advantages of the detached phenomena have influenced researchers to modify the conventional methods to promote it on the earth. Since 1994, the vertical directional solidification （VDS） technique has been employed for the growth of bulk crystals, without the seed, without contact to the ampoule wall, without coating and without external pressure. An automated furnace was designed and fabricated for the controlled temperature gradients, growth conditions and parameters. The typical ingots growths of GaSb have shown the gap of 20 μm-145 μm and mobility μn = 1125 cm^2/V.sec at 300 K. Mobility is highest and five times larger than the attached growths. Dislocation density is the order of 104/cm2 in the conical region, decreases in the direction of growth, and in many crystals reached less than 103/cm2. The spontaneous gap formation due to the meniscus depends on the pressure differences and thermal state. GaSb grown ingots have shown progress in the properties of crystal grown ever, and attributed to reduce thermal stress without contact to the ampoule wall.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61564002 and 11664005)the Guizhou Normal University Innovation and Entrepreneurship Education Research Center Foundation(Grant No.0418010)the Joint Foundation of Guizhou Normal University(Grant No.7341)
文摘Using first-principle calculations, we investigate the mechanical, structural, and electronic properties and formation energy of 25 kinds of Ⅲ–V binary monolayers in detail. A relative radius of the binary compound according to the atomic number in the periodic table is defined, and based on the definition, the 25 kinds of Ⅲ–V binary compounds are exactly located at a symmetric position in a symmetric matrix. The mechanical properties and band gaps are found to be very dependent on relative radius, while the effective mass of holes and electrons are found to be less dependent. A linear function between Young’s modulus and formation energy is fitted with a linear relation in this paper. The change regularity of physical properties of B–V(V = P, As, Sb, Bi) and Ⅲ–N(Ⅲ = Al, Ga, In, Tl) are found to be very different from those of other Ⅲ–V binary compounds.
文摘Complex VO(C\-\{12\}H\-\{12\}N\-2O\-2)(C\-\{13\}H\-\{10\}NO\-2)(C\-\{12\}H\-\{12\}N\-2O\+\{\{\}\+\{2-\}\}\-2=acetylacetone benzoylhydrozanate,C\-\{13\}H\-\{10\}NO\+_\-2=\%N\%\|phenylbenzohydroxamate) was synthesized and characterized by means of elemental analysis,IR and UV spectroscopies,cyclic voltammetry and single crystal X\|ray diffraction. The complex crystallized in the monoclinic system with space group \%P\%2\-1/\%n\% and the crystal cell parameters \%a\%=1\^3003(1) nm,\%b\%=0\^88836(6) nm,\%c\%=2\^0196(2) nm,\%β\%=95\^065(8)°,\%V\%=2\^3238(3) nm\+3,\%M\%\-r=495\^40 and \%Z\%=4. The two oxygen and one nitrogen atoms of the tridentate hydrazone ligand coordinate to the vanadium atom,forming an equatorial plane. And the coordinated vanadium atom exhibits a distorted octahedral geometry. The atom in the transposition to the oxo O atom is the carbonyl oxygen atom of the hydroxamate ligand in the complex. The half\|wave redox potential of the title complex in the three different solvents positively shifts in the order of CH\-2Cl\-2<CH\-3CN<DMF.
基金This work was supported by the State Key Laboratory of Structural Chemistry (030065) the Chinese Academy of Sciences the NNSFC (20073048) and the NSF of Fujian province (2002F015)
文摘The crystal structure of the title compound, [enH2][Fe{MoⅤ6O12(OH)3(HPO4)- (H2PO4)3}2]6en6H2O (en = H2NCH2CH2NH2), hydrothermally synthesized from a mixture of Na2MoO42H2O, Fe2(SO4)3, H3PO4, H2N(CH2)2NH2 and water, has been determined by single- crystal X-ray diffraction. The crystal is of triclinic, space group P?with a = 11.9014(1), b = 13.4246(2), c = 13.8719(2) , a = 87.465(1), b = 69.981(1), g = 64.960(1)? V = 1873.46(4) 3, Z = 1, Mr = 2997.89, F(000) = 1466, m = 2.427 mm-1 and Dc = 2.657 g/cm3. The final R = 0.0404 for 5570 observed reflections (I > 2s(I)). The structural analysis reveals that each cluster anion contains two coplanar {Mo6} rings of six edge-sharing Mo(O5OH) octahedra, and the two {Mo6} rings are linked together through one octahedral FeⅡ ion to generate a sandwich-type cluster with rigorous () symmetry. Moreover, these clusters are further linked into a three-dimensional frame- work by hydrogen bonds.
文摘etra ( N, N-diethyldithiocarbamates ) Samarium (Ⅲ)tetra (N, N-di-ethyldithiocarbamates) Molybdenum (V)([Mo (dtc)][Sm (dtc)])was synthesizedby the reaction of [Mo(dtc)]Cl and Na[Sm(dtc)] in miethanol. The crystal struc-ture was determined using X-ray diffraction methods. The compound crystallizes inthe triclinic space group P1 with the lattice parameters: a =1. 1557(4) nm, b=1.5253(3) nm, c=1. 8670 (6) nm and a=97.001 (20)°, β=94. 506(24)°, γ=93. 419(20)°,Z=2.The final R=0.059.The spectroscopic and XPS studies werecarried out.
文摘介绍以高能紫外激光为光源的、研究 MIS 结构电荷特性的光Ⅰ-Ⅴ法。简述了该法实验原理、实验装置和测试方法;给出了由传统热氧化的 SiO_2介质膜和新型快速热氮化的 SiOxNy 膜(缩写为 RTNF)组成的 MIS 结构的光Ⅰ-Ⅴ实验数据、体电荷密度和平均分布中心的实验结果。并就该法优缺点、应用前景及改进途径作了讨论.
基金supported by the Scientific Research Common Program of Beijing Municipal Commission of Education,PRC (KM200910028011)
文摘Divanadium（Ⅴ） complex [VO（aptch）（μ-OCH3）]2（1） and two monovanadium（Ⅴ） complexes [VO（apfah））（OEt）]（2a and 2b,H2aptch = 2-hydroxyacetophenone thiophene-2-car-boxylic hydrazone,H2apfah = 2-hydroxyacetophenone 2-furoic acid hydrazone） have been synthesized and characterized.Single-crystal X-ray diffraction studies reveal that 1 is a cen-trosymmetric dimer bridged by two methoxido O-atoms.Complex 1 crystallizes in the monoclinic crystal system,space groups P21/c with a = 7.4825（4）,b = 17.0928（11）,c = 11.6961（7） ,β = 98.172（4）o,Z = 2,F（000） = 728,μ = 0.829 mm-1,the final R = 0.0457 and wR = 0.1137 for 2654 observed reflections with I 〉 2（I）.The vanadium（V） is coordinated to the tridentate ligand,ethanol molecule to form a distorted square-pyramidal geometry,complexes 2a and 2b.Although 2a and 2b have the same asymmetric unit,they belong to different space groups.Complex 2a crystallizes in the monoclinic crystal system,space groups P21/n with a = 10.2293（2）,b = 15.6660（3）,c = 10.6298（2） ,β = 116.259（1）o,Z = 4,μ = 0.676 mm-1;complex 2b crystallizes in the triclinic crystal system,space groups P with a = 8.2808（4）,b = 9.4704（5）,c = 10.0819（5） ,α = 86.133（3）,= 81.956（3）,γ = 80.248（3）o,Z = 2 and μ = 0.670 mm-1.The hydrogen bonds are found to exist in 2b only.The crystal structure is stabilized by intermolecular hydrogen bonds of C-H···O.
文摘The development of new materials,having exceptional properties in comparison to existing materials is highly required for bringing advancement in electronic and optoelectronic technologies.Keeping this fact,we investigated structural,electronic,and optical properties of zincblende GaN doped with selected Zn concentrations(6.25%,12.50%,and 18.70%),using the first-principle calculations based on density functional theory with GGA+U.We conducted the entire study using the WIEN2K code.In this study,we calculated various significant parametric quantities such as cohesive energies,formation energies,bulk moduli,and lattice constants along with the study of optical and electronic properties by substituting Ga atoms with Zn atoms in 1×2×2 supercell.The structural stability is confirmed by studying the phonon dispersion curves which suggest that Zn:GaN material is stable against the 6.25%and 18.70%Zn concentrations while for 12.50%,it shows instability.The Hubbard values U=0,2,4,6 eV were added to GGA and the electronic properties were improved with the U=6 eV.Optical absorption was blue shifted while the refractive index and dielectric constant were increased with increasing the Zn concentrations.Electronic properties are enhanced due to the prime contribution of cations(Zn)3ri states.The optical and electronic properties are further discussed in detail in the entire study.
文摘Advantages of the detached phenomena have influenced researchers to modify the conventional methods to promote it on the earth. Since 1994, the vertical directional solidification （VDS） technique has been employed for the growth of bulk crystals, without the seed, without contact to the ampoule wall, without coating and without external pressure. An automated furnace was designed and fabricated for the controlled temperature gradients, growth conditions and parameters. The typical ingots growths of GaSb have shown the gap of 20 μm-145 μm and mobility μn = 1125 cm^2/V.sec at 300 K. Mobility is highest and five times larger than the attached growths. Dislocation density is the order of 104/cm2 in the conical region, decreases in the direction of growth, and in many crystals reached less than 103/cm2. The spontaneous gap formation due to the meniscus depends on the pressure differences and thermal state. GaSb grown ingots have shown progress in the properties of crystal grown ever, and attributed to reduce thermal stress without contact to the ampoule wall.
