scholarly journals Theory of the F-centers of Coloured Alakali Halides. Part II: Electronic Structure of F-centers - General Theory

1949 ◽  
Vol 4 (3) ◽  
pp. 243-250 ◽  
Author(s):  
T. Muto
Keyword(s):  
Electronic Structure ◽  
General Theory ◽  
F Centers

Thermodynamics of Defect Formation and Hydration of Y2O3

2012 ◽  
Vol 326-328 ◽  
pp. 126-131 ◽  
Author(s):  
L.P. Putilov ◽  
V.I. Tsidilkovski ◽  
A.N. Varaksin ◽  
Anatoly Yakovlevich Fishman
Keyword(s):  
Electronic Structure ◽  
Gas Phase ◽  
Defect Formation ◽  
Thermodynamic Description ◽  
Statistical Thermodynamic ◽  
Wide Range ◽  
F Center ◽  
Mechanical Approach ◽  
Quantum Mechanical Approach ◽  
F Centers

Defect formation in yttria with a small content of acceptor impurities in equilibrium with a hydrogen-containing gas phase is studied theoretically. A statistical-thermodynamic description of the yttriagas equilibrium is based on the approach developed for compounds with a complex electronic structure [Phys. Stat. Sol. B (1991) Vol. 168, p. 233]. The considered model of electronic structure for Y2O3 includes, besides valence and conduction bands, acceptor and F-center states. The energy of F-centers was calculated in the framework of the variational quantum-mechanical approach combined with the molecular statics method. It is shown that acceptor states appreciably affect the thermodynamics of defect formation, while the F-centers contribution in a wide range of external parameters is small. The concentrations of defects (protons, oxygen vacancies, electronic defects) and the Fermi level position are determined as functions of temperature and gas phase parameters.

Electronic Structure of the Ce Systems I. General Theory

1986 ◽  
Vol 137 (2) ◽  
pp. 533-539 ◽  
Author(s):  
F. López-Aguilar ◽  
J. Costa-Quintana
Keyword(s):  
Electronic Structure ◽  
General Theory

Electronic Structure of F-Centers in Alkaline Earth Fluorides

1967 ◽  
Vol 23 (2) ◽  
pp. 713-719 ◽  
Author(s):  
H. W. den Hartog ◽  
J. Arends
Keyword(s):  
Electronic Structure ◽  
Alkaline Earth ◽  
F Centers

Extreme self-sacrifice beyond fusion: Moral expansiveness and the special case of allyship

2018 ◽  
Vol 41 ◽  
Author(s):  
Daniel Crimston ◽  
Matthew J. Hornsey
Keyword(s):  
General Theory ◽  
Biological Markers ◽  
Natural Environment ◽  
Relevant Dimension ◽  
Special Case

AbstractAs a general theory of extreme self-sacrifice, Whitehouse's article misses one relevant dimension: people's willingness to fight and die in support of entities not bound by biological markers or ancestral kinship (allyship). We discuss research on moral expansiveness, which highlights individuals’ capacity to self-sacrifice for targets that lie outside traditional in-group markers, including racial out-groups, animals, and the natural environment.

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.

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