Electronic structure and charge state of atoms of cubic and hexagonal tantalum carbides

1999 ◽  
Vol 38 (5-6) ◽  
pp. 284-291 ◽  
Author(s):  
O. Yu. Khyzhun
Keyword(s):  
Electronic Structure ◽  
Charge State ◽  
Tantalum Carbides

Impact of Dopants on the PbTe Thermoelectric Efficiency

2010 ◽  
Vol 1267 ◽  
Author(s):  
Ka Xiong ◽  
Rahul P Gupta ◽  
John B White ◽  
Bruce Gnade ◽  
Kyeongjae Cho
Keyword(s):  
Experimental Data ◽  
Electronic Structure ◽  
Charge State ◽  
First Principles ◽  
First Principles Calculations ◽  
Defect Level ◽  
Thermoelectric Efficiency ◽  
Group Iii ◽  
The Impact

AbstractWe investigated the impact of doping group III elements (Al, Ga, In and Tl) on the electronic structure of PbTe by first principles calculations. The impurity-induced defect level changes with respect to the charge state of the impurity. We find that among the four elements, Tl is the best candidate for the enhancement of thermoelectric efficiency, consistent with the experimental data.

Electronic structure variation of the surface and bulk of a LiNi0.5Mn1.5O4cathode as a function of state of charge: X-ray absorption spectroscopic study

2014 ◽  
Vol 16 (27) ◽  
pp. 13838-13842 ◽  
Author(s):  
Jigang Zhou ◽  
Da Hong ◽  
Jian Wang ◽  
Yongfeng Hu ◽  
Xiaohua Xie ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Spectroscopic Study ◽  
Charge State ◽  
State Of Charge ◽  
Structure Variation ◽  
X Ray ◽  
Electrochemical Cycling ◽  
X Ray Absorption ◽  
Bulk Structures

The electronic structure of Li1−xNi0.5Mn1.5O4as a function of the charge state shows different roles of the constituent atoms, and the surface and bulk structures change upon electrochemical cycling.

Au encapsulated into Al-MCM-41 mesoporous material: in situ synthesis and electronic structure

RSC Advances ◽  
2015 ◽  
Vol 5 (26) ◽  
pp. 20414-20423 ◽  
Author(s):  
Liangjie Fu ◽  
Chengli Huo ◽  
Xi He ◽  
Huaming Yang
Keyword(s):  
Electronic Structure ◽  
Charge State ◽  
Mesoporous Material ◽  
In Situ Synthesis ◽  
One Step ◽  
Mcm 41

A facile one-step technique is proposed for the successful synthesis of highly ordered Au/Al-MCM-41. The charge state of Au3+ in the mesoporous framework was partially reduced due to the accompanying Al when clay was used as source.

Electronic Structure and Charge State of Oxygen Vacancies in Perfect ZrO2 Crystals

1990 ◽  
Vol 162 (1) ◽  
pp. 165-171 ◽  
Author(s):  
A. B. Sobolev ◽  
A. N. Varaksin ◽  
O. A. Keda ◽  
A. P. Khaimenov
Keyword(s):  
Electronic Structure ◽  
Charge State ◽  
Oxygen Vacancies

EELS Measurement of the Local Electronic Structure of Copper Atoms Segregated to Aluminum Grain Boundaries

1996 ◽  
Vol 54 ◽  
pp. 342-343
Author(s):  
S.J. Splinter ◽  
J. Bruley ◽  
P.E. Batson ◽  
D.A. Smith ◽  
R. Rosenberg
Keyword(s):  
Electronic Structure ◽  
Grain Boundaries ◽  
Boundary Segregation ◽  
Thin Layers ◽  
Nominal Composition ◽  
Spatially Resolved ◽  
Service Lifetime ◽  
Heat Treated ◽  
Probe Size ◽  
Local Electronic Structure

It has long been known that the addition of Cu to Al interconnects improves the resistance to electromigration failure. It is generally accepted that this improvement is the result of Cu segregation to Al grain boundaries. The exact mechanism by which segregated Cu increases service lifetime is not understood, although it has been suggested that the formation of thin layers of θ-CuA12 (or some metastable substoichiometric precursor, θ’ or θ”) at the boundaries may be necessary. This paper reports measurements of the local electronic structure of Cu atoms segregated to Al grain boundaries using spatially resolved EELS in a UHV STEM. It is shown that segregated Cu exists in a chemical environment similar to that of Cu atoms in bulk θ-phase precipitates.Films of 100 nm thickness and nominal composition Al-2.5wt%Cu were deposited by sputtering from alloy targets onto NaCl substrates. The samples were solution heat treated at 748K for 30 min and aged at 523K for 4 h to promote equilibrium grain boundary segregation. EELS measurements were made using a Gatan 666 PEELS spectrometer interfaced to a VG HB501 STEM operating at 100 keV. The probe size was estimated to be 1 nm FWHM. Grain boundaries with the narrowest projected width were chosen for analysis. EDX measurements of Cu segregation were made using a VG HB603 STEM.

Electronic structure studies of conducting polymers by electron energy-loss spectroscopy

1996 ◽  
Vol 54 ◽  
pp. 160-161
Author(s):  
J. Fink
Keyword(s):  
Electronic Structure ◽  
Conducting Polymers ◽  
Conjugated Polymers ◽  
Electron Acceptors ◽  
Electron Donors ◽  
Light Emitting ◽  
One Dimensional ◽  
New Class ◽  
Electrical Conductivities ◽  
Electron Energy Loss

Conducting polymers comprises a new class of materials achieving electrical conductivities which rival those of the best metals. The parent compounds (conjugated polymers) are quasi-one-dimensional semiconductors. These polymers can be doped by electron acceptors or electron donors. The prototype of these materials is polyacetylene (PA). There are various other conjugated polymers such as polyparaphenylene, polyphenylenevinylene, polypoyrrole or polythiophene. The doped systems, i.e. the conducting polymers, have intersting potential technological applications such as replacement of conventional metals in electronic shielding and antistatic equipment, rechargable batteries, and flexible light emitting diodes.Although these systems have been investigated almost 20 years, the electronic structure of the doped metallic systems is not clear and even the reason for the gap in undoped semiconducting systems is under discussion.

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