Structure, electronic properties and electron energy loss spectra of transition metal nitride films

2013 ◽  
Vol 528 ◽  
pp. 49-52 ◽  
Author(s):  
L.E. Koutsokeras ◽  
G.M. Matenoglou ◽  
P. Patsalas
Author(s):  
D. H. Pearson ◽  
C. C. Ahn ◽  
B. Fultz ◽  
P. Rez

A straightforward method for measuring the white line intensities of the L23 absorption edges of 3d transition metal electron energy loss spectra was recently reported by Pearson et al. [1]. In that analysis, the white line intensities were isolated by assuming that the continuum contribution for the 3d metals could be approximated by an edge shape similiar to that of copper, which has a full 3d band. When normalized to the continuum, the white line intensities were found to decrease linearly with atomic number (or 3d state occupancy). A similar analysis for the 4d metals showed that the white line intensities initially increased, peaked at Nb, and then decreased nearly linearly with atomic number [2]. The white line calculations of Ahn et al. were in qualitative agreement with these results for the 4d metals, but deviated from experimental results for the early 3d metals [3]. In an effort to determine if the continuum L23 edge is indeed copper-like for the early 3d metals we have calculated the continuum edge shapes based on an atomic, one electron model.


Author(s):  
Eckhard Quandt ◽  
Stephan laBarré ◽  
Andreas Hartmann ◽  
Heinz Niedrig

Due to the development of semiconductor detectors with high spatial resolution -- e.g. charge coupled devices (CCDs) or photodiode arrays (PDAs) -- the parallel detection of electron energy loss spectra (EELS) has become an important alternative to serial registration. Using parallel detection for recording of energy spectroscopic large angle convergent beam patterns (LACBPs) special selected scattering vectors and small detection apertures lead to very low intensities. Therefore the very sensitive direct irradiation of a cooled linear PDA instead of the common combination of scintillator, fibre optic, and semiconductor has been investigated. In order to obtain a sufficient energy resolution the spectra are optionally magnified by a quadrupole-lens system.The detector used is a Hamamatsu S2304-512Q linear PDA with 512 diodes and removed quartz-glas window. The sensor size is 13 μm ∗ 2.5 mm with an element spacing of 25 μm. Along with the dispersion of 3.5 μm/eV at 40 keV the maximum energy resolution is limited to about 7 eV, so that a magnification system should be attached for experiments requiring a better resolution.


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