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1.
We present the first evidence of direct measurement of relative Fermi energies in alloys and between pure metals. From applying the “atomic” concept of core hole final state screening, the Auger energy shift of noble metal A equals EFA?EF(x). High resolution Auger shifts in P1?xtCux,AuxCu1?x and AuxAg1?x demonstrate experimental verification of this simple relation. We find EFCuEFAu ? ? 0.2 eV, and EFPt ? EFCu and EFAg ? EFAu. 相似文献
2.
D. Cheng D. Cao 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,66(1):17-23
Canonical ensemble Monte Carlo simulations are applied to investigate the
melting of the icosahedral 55-atom Ag-Cu-Au clusters. The clusters are
modeled by the second-moment approximation of the tight-binding (TB-SMA)
many-body potentials. Results show that the introduction of the only Cu atom
of the third alloying metal in the bimetallic Ag43Au12 cluster,
forming the Ag42Cu1Au12 cluster, can greatly increase the
melting point of the cluster by about 100 K. It is also found that the
substitution of the only Cu atom of the third alloying metal in the
Ag1Au54 clusters, forming the Ag1Cu1Au53 cluster,
can result in an increase of 40 K in the melting point. It can be concluded
that the melting points of the bimetallic clusters can be tuned by the third
metal impurities doping. In addition, the surface segregation of Ag atoms in
the Ag-Cu-Au trimetallic clusters occurs even after melting. 相似文献
3.
J. Humliček F. Lukeš E. Schmidt M.G. Kekoua E. Khoutsishvili 《Solid State Communications》1983,47(5):387-389
he E2 transitions in GeSi alloys are analyzed quantitatively using low-field electroreflectance data. The model of M1 saddle point transitions is found to be in fair agreement with differentiated electroreflectance spectra in the whole composttion range. The broadening parameter of pure Ge and Si increases by 0.035 eV in the alloy with equal content of both components. 相似文献
4.
《Solid State Communications》1986,58(2):143-146
Mn Lα emission spectra of pure metal and AlMn, CuMn and NiMn alloys are presented. For CuMn and NiMn alloys, the dependence of the width of structureless emission band on Mn concentration is discussed. For Al0.995Mn0.005 alloy, distoted shape of the emission spectrum reveals the spin splitting of impurity virtual bound states. 相似文献
5.
Polycrystalline Ag, Ag20Au80, Ag40Au60, Ag80Au20 and Au samples were bombarded with 15 keV Ar+ at 60° incidence and the resulting secondary neutral yield distribution was studied by non-resonant laser postionisation mass spectrometry. Neutral clusters containing up to 21 atoms were observed for the targets. The yield of neutral clusters, AgmAun−m, containing n atoms, Yn, was found to follow a power in n, i.e. Yn ∝ n−δ, where the exponent δ varied from 3.2 to 4.0. For a fixed n, the cluster yields showed a variation with number of gold atoms similar to that expected for a binomial distribution. In addition, the cluster compositions from the sputtered alloys were indicative of sputtering from a gold rich surface. 相似文献
6.
Valence and core level spectra ofAgMn,AuFe,AuCo,AuNi,CuFe,CuCo andCuNi will be reported. Clearly defined virtual bound states (vbs) can only be detected in the spin fluctuating systemsAuNi andCuNi. An increase in the density of states near the Fermi energy, in the region of the flats-p band of the host metal is observed in the other magnetic alloys. There are indications that a large hybridization between the impurity and the host metald-electrons exist. The impurity core levels show satellites. They can originate from the emission from real isolated impurities and from many body effects. 相似文献
7.
《Journal of Electron Spectroscopy and Related Phenomena》2004,136(3):235-238
High resolution core level photoelectron spectra for a series of AgxPd1−x alloys have been measured and reveal a large “disorder broadening” effect. A comparison of measurements of this effect for three alloy systems, AgxPd1−x, CuxPd1−x and CuxZn1−x, with results of ab initio calculations is presented. Poor agreement is obtained and possible reasons for this observation are discussed. 相似文献
8.
Measurements of the electrical resistivity as a function of temperature from 250 to 270 K for Au and f.c.c. phase AuGa alloys are presented. The linear dependence of the resistivity with temperature and previous results of the superconducting transition temperature of the alloys are used to obtain a value for Tc of pure Au. From these results a new method is introduced to estimate the Coulomb pseudopotential μ1 for gold. 相似文献
9.
The initial oxidation behavior of Cu0.5Au0.5 (0 0 1) thin film was investigated by in situ ultrahigh vacuum transmission electron microscopy to model nano-oxidation of alloys with one active component and one noble component. The formation of irregular-shaped octahedron Cu2O islands with cube-on-cube crystallographic orientation to the substrate film was observed at all temperature studied. The energetics of Cu2O nucleation for Cu and Cu0.5Au0.5 oxidation was compared. Cu0.5Au0.5 oxidation has lower nucleation activation energy due to the reduced mismatch strain between Cu2O and Cu0.5Au0.5 films. On the other hand, the reaction kinetics for Cu0.5Au0.5 alloy oxidation is slower due to the higher diffusion activation energy of Cu. 相似文献
10.
The synthesis of high temperature superconducting phases in the NbGe, NbSn, VSi, VGe, VSn, NbC and MoC systems is described by method consisting in the thermolysis of volatile hydrides or organometallic compounds on resistively heated wires. For face-centred cubic NbC a higher transition temperature than previously reported was obtained. The A15 phase boundary of NbGe is extended towards the stoichiometric 3:1 composition, affording samples of Nb3 Ge with a Tc onset of 15.8°K. 相似文献
11.
Thermal evaporation, flash evaporation and rf-sputtering techniques were applied to the preparation of amorphous films of superionic conducting glasses in the systems AgIAg2MoO4 and AgIAg2OB2O3. The flash-evaporated films were amorphous and showed very high conductivities, about 2 × 10?2S/cm for the AgIAg2MoO4 and about 5 × 10?3S/cm for the AgIAg2OB2O3 at room temperature, and gave a Ag+ transport number of unity. The thermal evaporation method produced crystalline-phase included films. The rf-sputtered films were amorphous by X-ray diffraction and the transport number of Ag+ ions was smaller than unity (about 0.9). Thus flash evaporation was concluded to be the most suitable method for preparing amorphous films of superionic conducting glasses. 相似文献
12.
以AgNO3,HAuCl4和正硅酸乙酯为主要原料,利用溶胶-凝胶法和旋涂技术,通过热处理和紫外光辐射还原得到了不同nAg/nAu(1∶0,2∶1,1∶2,0∶1)的Ag-Au合金/SiO2复合薄膜.从扫描电子显微镜和X射线衍射谱的结果可以看出得到的薄膜均匀性好,复合薄膜中合金颗粒的尺寸为10 nm左右.利用紫外-可见分光光谱仪研究了复合薄膜的光吸收性能,结果表明,随着nAg/nAu的降低,吸收峰的位置也由最初的Ag纳米粒子的等离子共振吸收峰430 nm附近,逐渐红移到Au纳米粒子的等离子共振吸收峰605和880 nm附近.从光吸收谱可以看出,nAg∶nAu=2∶1和1∶2的两个样品分别在515,730 nm附近和550,730 nm附近出现表面等离子共振吸收峰.这表明Au-Ag合金固溶体的形成.
关键词:
2')" href="#">Ag-Au合金/SiO2
紫外辐射
光吸收性能 相似文献
13.
N.?I.?Kourov V.?G.?Pushin A.?V.?Korolev Yu.?V.?Knyazev L.?N.?Bu?nova N.?V.?Gokhfel’d V.?P.?Pilyugin 《Physics of the Solid State》2010,52(1):12-17
The electrical, magnetic, and optical properties of the Cu72Au24Ag4 ternary alloy in the ordered and disordered states have been studied by the method of severe torsional plastic deformation
under pressure in Bridgman anvils. It has been shown that, as a result of this deformation, the residual electrical resistivity
of the alloy increases by approximately 11% and the magnitude of the negative thermopower decreases. The high diamagnetic
susceptibility of the alloy has been explained by a significant role of charge carriers with the effective mass considerably
smaller than the free-electron mass. The behavior of the optical conductivity has been discussed with due regard for the results
of energy-band calculations. The experimental data obtained for the Cu72Au24Ag4 alloy have been compared with the results of similar studies of the Cu3Au binary alloy. 相似文献
14.
Impurity 51V nuclear relaxation time T1 in AuV Kondo alloys was measured in the temperature range 78–540 K, which includes the Kondo temperature TK of ~300 K. Considerable deviation from Korringa's relation was observed. 相似文献
15.
We have measured the properties of some Pd1?xMnx and Pd1?xMnxHy alloys using a low field a.c. technique. For x<4%, we observe a change over from ferromagnetism (when y = 0) to antiferromagnetism (when y ≌ 0.7). The properties of the hydrogenated alloys are compared with the similar Mn alloys. 相似文献
16.
The model of randomly oriented single-ion uniaxial anisotropy field is extended to the case of antiferromagnetic exchange interaction between rare-earth ions. A self-consistent two-spin cluster approximation is used to calculate the magnetization curves for a model system of spin 1. The results are in good qualitative agreement with experimental data on amorphous RExCu1?x and RExAg1?x alloys (RE = Tb, Dy, Ho). In particular, the observed increase of the “coercive” field with increasing x in RExCu1?x alloys is accounted for. 相似文献
17.
C. Van Haesendonck L. van der dries Y. Bruynseraede A. Gilabert 《Solid State Communications》1980,35(10):805-807
The temperature dependence of the conduction electron spin-flip lifetime in CuCr Kondo alloys can be determined from Tc measurements in CuCr/Pb proximity sandwiches. When the thin film sandwich is in the Cooper limit, a great sensitivity of the magnetic depairing effect upon Tc is observed. The temperature dependence of the calculated pair breaking parameter deviates markedly from the theoretical predictions. 相似文献
18.
ABSTRACTWe report a theoretical investigation of neutral AuxAgyCuz and cationic AuxAgyCuz+ ternary clusters, for x?+?y+z?=?5 and 6. Our study is performed within density functional theory at the TPSSTPSS/SDD level. The geometries, chemical order, binding energy, mixing energy, second difference in the energy, adiabatic ionisation potential of these clusters are evaluated as a function of the whole concentration range. The most probable dissociation channels and the corresponding dissociation energies for the most stable clusters are also determined and discussed. 相似文献
19.
A.P. Murani 《Solid State Communications》1973,12(4):295-298
Electrical resistivity measurements on dillute alloys of Ce, Gd and Yb in Au are reported. Both Ce and Gd alloys show negligible temperature dependence in their excess resistivity at low temperatures whereas the Kondo effect is unambigously observed in the case of . This result correlates with a negative exchange constant found for in the EPR experiment of Tao and co-workers. 相似文献
20.
Using an atomic beam magnetic resonance apparatus the nuclear magnetic dipole momentμ I of the stable isotope Au197 was measured directly with the doublet method. The result isμ I(Au197)=0.143491 (9)μ n, uncorrected for atomic diamagnetism. Further hyperfine structure measurements were performed in the ground states of K39, Ag107, Ag109 and Au197 with the following results:Δv(K39)=461.719723 (38) MHzΔv(Ag107)=1712.512111 (18) MHzΔv(Ag109)=1976.932075 (17) MHzΔv(Au197)=6099.320184 (13) MHzg J(Ag107)/g J(K39)=1.0000260 (20)g J(Au197)/g J(K39)=1.0005076 (20). 相似文献