Disorder broadening of alloy Auger spectra

Auger spectroscopy promises the means to separate initial and final state contributions to the disorder broadening of core XPS spectra in disordered alloys. Auger disorder broadening, deduced from recent ab initio results, is predicted to be greater than XPS disorder broadening for Cu₅₀Pd₅₀ and Ag₅₀Pd₅₀ alloys. Simulations are used to assess whether this effect is observable experimentally despite the greater lifetime broadening of Auger spectra. A number of cases where narrow core–core–core Auger transitions should allow clear experimental identification of this effect are identified. The prospects for determining environment-resolved Auger spectra using APECS have been investigated.     

Auger electron and characteristic energy loss spectra of plutonium

The Auger electron and characteristic loss spectra of plutonium have been obtained for the first time using a four grid retarding potential analyzer. The surface of this reactive metal was prepared by scribing in situ in good vacuum with a titanium carbide blade. Oxygen and carbon impurities were still present after scribing. The origin of the Auger electron and loss peaks is suggested, and a correlation is made with the peaks observed for uranium dioxide by Ellis and Campbell.     

High resolutionLMM Auger spectra of low energy from solid surfaces

LMM Auger spectra of Cl, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, and Zn have been investigated with an electrostatic cylindrical spectrometer with energy resolution of about 0.05% in the energy range of 100 eV–1 keV. The Auger electrons have been excited by 5 keV electron bombardment at a grazing incidence angle and the peak of elastically scattered primary electrons have been used for calibration. The line assignments have been discussed.     

Characteristic energy loss and Auger electron spectra of GaP (110)

The characteristic energy loss and Auger electron spectra of clean GaP (110) have been measured with a four grid retarding field analyser. A peak in the loss spectrum has been found at 11.2 eV which is probably due to a surface plasma loss. The remaining structure has been assigned to direct interband transitions, to single and double bulk plasma losses and to d-band transitions by analogy with previous optical and electron transmission studies. Suggestions are made as to the origin of the peaks in the Auger spectrum and changes in the spectrum in the presence of oxygen are discussed.     

Solid state broadening effects in the Auger spectrum of xenon

The M_4,5N_4,5 Auger spectrum has been measured at high resolution from solid xenon. Comparison with the gas phase data shows that considerable broadening of the Auger lines occurs in the solid. Electron energy loss data is also reported for solid xenon.     

Auger spectra for elements of low atomic number

KLL Auger spectra for the light elements sodium (Z=11) and magnesium (Z=12) have been studied. All five lines predicted by the extremeLS coupling theory are observed. A comparison is made with intensities predicted by the inter-configuration interaction theory ofAsaad. Agreement is obtained for the transition intensities to the three differentKLL configurations; however, theory does not give correct relative intensities within the 2s ² 2p ⁴ configuration. The measured Auger energies are compared with those calculated from the semi-empirical expression ofAsaad andBurhop and modified byHörnfeldt et al. Good agreement is obtained when we use electron binding energies measured by the ESCA method.     

Al激光等离子体Stark加宽光谱观测

用YAG脉冲激光器产生的1.06μm激光,在高真空下轰击Al靶,观测到9条AlⅠ,AlⅡ和AlⅢ的等离子体谱线。利用高分辨率双光栅单色仪和光学多道分析仪(OMA),对谱线的Stark加宽和线型进行了测量。得到Al等离子体的电子密度沿靶面法向的分布,测得电子密度在1.0×l017～1.l×l018cm-3范围。利用谱线峰值法估算了等离子体的温度约为1.5×l05K。测量结果与半经典理论的计算基本符合     

Isotopic effect in the broadening of the energy spectra of fragments of hydrogen molecular ions scattered from surface

The effect of broadening of the energy spectra of fragments of different hydrogen molecular ions scattered from a tungsten surface has been investigated experimentally and by computer simulation. The experimental results are approximated within the explosive model. The contributions of different mechanisms to the broadening of the energy spectra of scattered fragments are discussed.     

Energy parameter and the free-atom behavior of Auger spectra

The L₃M₄₅M₄₅ spectra of V and Cr do not exhibit free atom behavior, in sharp contrast to those of Cu and Zn. An energy difference parameter, Δ ?, derived entirely from observable energies, has been introduced to correlate with the extent of electron localization and free-atom behavior in Auger transitions.     

Error sources for the analysis of Doppler broadening in positron annihilation spectra

Correction factors for systematic shifts of the second-order moment ² (linearly related toS ^–1) of the Doppler broadened annihilation gamma ray lineshape are presented. They allow to compare ² values obtained under different experimental conditions. The height of the observed peak, the number of keV/channels used and the number of channels over which the Doppler broadening dsstribution should be considered are bounded by the a priori settled relative uncertainty ofgs ².Fellow of the CIC, PciA Bs. As., Argentina     

Parameters used for Doppler broadening spectra of positron annihilation γ-rays

The relationship between some popularly used arbitrary parameters and the variance of the Doppler broadening spectra of positron annihilation γ-rays is discussed. The experimental results are found to agree well with the theoretically derived formulas.