Two types of charge transfer excitations in low dimensional cuprates: an electron energy-loss study

2004 ◽  
Vol 137-140 ◽  
pp. 469-473 ◽  
Author(s):  
M. Knupfer ◽  
J. Fink ◽  
S.-L. Drechsler ◽  
R. Hayn ◽  
J. Malek ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Energy Loss ◽  
Electron Energy ◽  
Low Dimensional ◽  
Electron Energy Loss

Charge transfer in binary alloys: A future for electron energy loss spectroscopy in materials science

1988 ◽  
Vol 46 ◽  
pp. 2-5
Author(s):  
C. C. Ahn ◽  
D. H. Pearson ◽  
B. T. Fultz
Keyword(s):  
Charge Transfer ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Bound States ◽  
Binary Alloys ◽  
Threshold Energy ◽  
Enthalpies Of Formation ◽  
White Line ◽  
Electron Energy Loss

The redistribution of atomic charge which takes place from an atom of one type to that of another in a binary alloy system is fundamental to the formulation of models of enthalpies of formation of these systems. Of special interest are charge transfers where one of the alloy constituents is from the first row transition series. The extent to which the 3d band is filled, ultimately plays an important role in the propensity with which alloys will form intermetallic phases. An understanding of electron charge transfer is important not only in crystalline systems but can also serve as the basis for the determination of the extent of chemical short range order (CSRO) in amorphous binary alloys.Electron energy loss spectroscopy (EELS) in the electron microscope can probe unoccupied bound states and unlike other spectroscopies which probe core levels, is not surface sensitive. The features of the energy loss spectra of the 3d metals which make charge transfer studies possible are the L23 transitions. These spectra are characterized by two “white lines” at the threshold energy which result from ionizations from the 2p3/2 and 2p1/2 spin orbit subshells to a narrow bound 3d state. Beneath and beyond the white line transitions are transitions to the continuum states.

An electron energy-loss study of picene and chrysene based charge transfer salts

2015 ◽  
Vol 142 (18) ◽  
pp. 184702 ◽  
Author(s):  
Eric Müller ◽  
Benjamin Mahns ◽  
Bernd Büchner ◽  
Martin Knupfer
Keyword(s):  
Charge Transfer ◽  
Energy Loss ◽  
Electron Energy ◽  
Charge Transfer Salts ◽  
Electron Energy Loss

The Change of D-Electron Occupancy in TiNi and Ni3Ti Compounds Measured from the White-Line Intensity of Electron Energy Loss Spectroscopy

2012 ◽  
Vol 538-541 ◽  
pp. 2350-2353
Author(s):  
Wei Guo Yang
Keyword(s):  
Charge Transfer ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Line Intensity ◽  
White Line ◽  
Charge Neutrality ◽  
Charge Transfer Mechanism ◽  
Local Charge ◽  
Electron Energy Loss

The electron energy loss spectroscopy (EELS) of pure Ti, TiNi, Ni3Ti and pure Ni has been acquired and d-electron occupancy of both Ti and Ni in the metals has been measured from the white-line intensity. It is found that the change of d-electron occupancy of Ni is very small in all metals, but the d-electron occupancy of Ti in Ni3Ti increases considerable large relative to pure Ti. The change of d-electron occupancy is discussed in terms of charge transfer mechanism, local charge neutrality (LCN) approximation, and hybridization.

scholarly journals Momentum-Dependent Charge Transfer Excitations inSr2CuO2Cl2Angle-Resolved Electron Energy Loss Spectroscopy

1996 ◽  
Vol 77 (9) ◽  
pp. 1809-1812 ◽  
Author(s):  
Y. Y. Wang ◽  
F. C. Zhang ◽  
V. P. Dravid ◽  
K. K. Ng ◽  
M. V. Klein ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Electron Energy Loss

Data Acquisition and Handling Unit for a Quantitative Use of Electron Energy Loss Spectroscopy

1977 ◽  
Vol 35 ◽  
pp. 232-233 ◽  
Author(s):  
P. Trebbia ◽  
P. Ballongue ◽  
C. Colliex
Keyword(s):  
Electron Microscope ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Single Channel ◽  
Detection System ◽  
Surface Barrier ◽  
Solid State Detector ◽  
Electrostatic Mirror ◽  
Electron Energy Loss

An effective use of electron energy loss spectroscopy for chemical characterization of selected areas in the electron microscope can only be achieved with the development of quantitative measurements capabilities.The experimental assembly, which is sketched in Fig.l, has therefore been carried out. It comprises four main elements.The analytical transmission electron microscope is a conventional microscope fitted with a Castaing and Henry dispersive unit (magnetic prism and electrostatic mirror). Recent modifications include the improvement of the vacuum in the specimen chamber (below 10-6 torr) and the adaptation of a new electrostatic mirror.The detection system, similar to the one described by Hermann et al (1), is located in a separate chamber below the fluorescent screen which visualizes the energy loss spectrum. Variable apertures select the electrons, which have lost an energy AE within an energy window smaller than 1 eV, in front of a surface barrier solid state detector RTC BPY 52 100 S.Q. The saw tooth signal delivered by a charge sensitive preamplifier (decay time of 5.10-5 S) is amplified, shaped into a gaussian profile through an active filter and counted by a single channel analyser.

Trends in Electron Energy Loss Spectroscopy

1977 ◽  
Vol 35 ◽  
pp. 228-229
Author(s):  
C. Colliex ◽  
P. Trebbia
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Materials Science ◽  
Analytical Technique ◽  
Recent Developments ◽  
Quantitative Results ◽  
Electron Microscopes ◽  
Electron Energy Loss ◽  
Primary Electrons

The physical foundations for the use of electron energy loss spectroscopy towards analytical purposes, seem now rather well established and have been extensively discussed through recent publications. In this brief review we intend only to mention most recent developments in this field, which became available to our knowledge. We derive also some lines of discussion to define more clearly the limits of this analytical technique in materials science problems.The spectral information carried in both low ( 0<ΔE<100eV ) and high ( >100eV ) energy regions of the loss spectrum, is capable to provide quantitative results. Spectrometers have therefore been designed to work with all kinds of electron microscopes and to cover large energy ranges for the detection of inelastically scattered electrons (for instance the L-edge of molybdenum at 2500eV has been measured by van Zuylen with primary electrons of 80 kV). It is rather easy to fix a post-specimen magnetic optics on a STEM, but Crewe has recently underlined that great care should be devoted to optimize the collecting power and the energy resolution of the whole system.

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