scholarly journals Моделирование твердых растворов NaGd(MoO-=SUB=-4-=/SUB=-)-=SUB=-2-=/SUB=-- NaEu(MoO-=SUB=-4-=/SUB=-)-=SUB=-2-=/SUB=- и Na-=SUB=-2-=/SUB=-Gd-=SUB=-4-=/SUB=-(MoO-=SUB=-4-=/SUB=-)-=SUB=-7-=/SUB=--Na-=SUB=-2-=/SUB=-Eu-=SUB=-4-=/SUB=-(MoO-=SUB=-4-=/SUB=-)-=SUB=-7-=/SUB=- методом межатомных потенциалов

2019 ◽  
Vol 61 (4) ◽  
pp. 678
Author(s):  
В.Б. Дудникова ◽  
Е.В. Жариков ◽  
Н.Н. Еремин
Keyword(s):  
Solid Solutions ◽  
Atomistic Simulation ◽  
Statistical Distribution ◽  
Partial Ordering ◽  
Interatomic Potentials ◽  
Vibrational Entropy ◽  
Solid State Lasers ◽  
General Utility ◽  
Gadolinium Molybdate

AbstractSimulation of the solid solutions in the system of double sodium–gadolinium and sodium–europium molybdates, which are promising matrices for solid state lasers and phosphors has been carried out by the method of interatomic potentials. Two types of solid solutions have been studied, one of which contains finite components corresponding to the stoichiometric NaGd(MoO_4)_2–NaEu(MoO_4)_2 compositions with statistical distribution of cations in the crystal lattice. Another object is a cation-deficient Na_2Gd_4(MoO_4)_7–Na_2Eu_4(MoO_4)_7 system, in which we have examined the variants of statistical distribution and partial ordering of cations over structural positions. Atomistic simulation has been performed using the GULP 4.0.1 software package (General Utility Lattice Program). It is shown that when we pass from sodium-gadolinium molybdate to sodium-europium molybdate, both of stoichiometric and cation-deficient compositions, an increase in the unit cell volume is observed, while the density of the crystal, the energy of interatomic interactions in the structure, the vibrational entropy and the heat capacity decrease along with increasing europium content. The energy of interatomic interactions in the structure for cation-deficient solid solutions is less than for stoichiometric ones. Other aforementioned characteristics for cation-deficient solid solutions have greater values than for stoichiometric ones. The role of cluster europium centers in concentration quenching in NaGd(MoO_4)_2–NaEu(MoO_4)_2 solid solutions has been examined.

scholarly journals Энергетическое обоснование образования димеров иттербия в монокристаллах форстерита

2019 ◽  
Vol 61 (4) ◽  
pp. 737
Author(s):  
В.Б. Дудникова ◽  
Е.В. Жариков ◽  
Д.А. Лис ◽  
Н.Н. Еремин
Keyword(s):  
Computer Simulation ◽  
Software Package ◽  
Atomistic Simulation ◽  
Statistical Distribution ◽  
Energy Reduction ◽  
Crystallographic Axis ◽  
Significant Gain ◽  
General Utility ◽  
A Chain

AbstractA structural computer simulation of ytterbium-containing forsterite crystals has been carried out. Atomistic simulation is performed using the GULP 4.1 software package (General Utility Lattice Program). Different mechanisms of ytterbium dissolution in forsterite crystals are considered, and the dissolution energies of isolated defects, as well as charged and neutral clusters of various configurations, are calculated. The results of the calculation manifest that the formation of ytterbium clusters with a magnesium vacancy gives a significant gain in the dissolution energy. The formation of neutral clusters (dimers) in the M1 site (Yb_Mg1ν_Mg1Yb_Mg1) leads to an energy reduction by 1.7 eV compared with the statistical distribution of defects. As a result of simulation, it is shown the energetic substantiation of the formation of ytterbium dimers in forsterite crystals. A model of the most energetically favorable center in the M1 site is proposed—a dimer, consisting of a pair of trivalent ytterbium ions with a magnesium vacancy between them, forming a chain parallel to the crystallographic axis c .

Role of Mechanical Stresses at Ion Implantation of CdHgTe Solid Solutions

2013 ◽  
Vol 58 (9) ◽  
pp. 872-880 ◽  
Author(s):  
Smirnov A.B. Smirnov A.B. ◽  
◽  
Lytvyn O.S. Lytvyn O.S. ◽  
Morozhenko V.A. Morozhenko V.A. ◽  
Savkina R.K. Savkina R.K. ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Solid Solutions ◽  
Mechanical Stresses

scholarly journals Inequalities in the European Union—A Partial Order Analysis of the Main Indicators

2021 ◽  
Vol 13 (11) ◽  
pp. 6278
Author(s):  
Lars Carlsen ◽  
Rainer Bruggemann
Keyword(s):  
Indicator System ◽  
Partial Ordering ◽  
Disposable Income ◽  
The European Union ◽  
Member States ◽  
Eu Member States ◽  
Per Capita ◽  
Educational Aspect ◽  
The Eu

The inequality within the 27 European member states has been studied. Six indicators proclaimed by Eurostat to be the main indicators charactere the countries: (i) the relative median at-risk-of-poverty gap, (ii) the income distribution, (iii) the income share of the bottom 40% of the population, (iv) the purchasing power adjusted GDP per capita, (v) the adjusted gross disposable income of households per capita and (vi) the asylum applications by state of procedure. The resulting multi-indicator system was analyzed applying partial ordering methodology, i.e., including all indicators simultaneously without any pretreatment. The degree of inequality was studied for the years 2010, 2015 and 2019. The EU member states were partially ordered and ranked. For all three years Luxembourg, The Netherlands, Austria, and Finland are found to be highly ranked, i.e., having rather low inequality. Bulgaria and Romania are, on the other hand, for all three years ranked low, with the highest degree of inequality. Excluding the asylum indicator, the risk-poverty-gap and the adjusted gross disposable income were found as the most important indicators. If, however, the asylum application is included, this indicator turns out as the most important for the mutual ranking of the countries. A set of additional indicators was studied disclosing the educational aspect as of major importance to achieve equality. Special partial ordering tools were applied to study the role of the single indicators, e.g., in relation to elucidate the incomparability of some countries to all other countries within the union.

Role of Sm3+ on Mn Nanoparticles Embedded Zinc Tellurite Glasses Absorption and Luminescence Characteristic

2020 ◽  
Vol 981 ◽  
pp. 73-77
Author(s):  
Nurul Ainaa Najihah Busra ◽  
Ramli Arifin ◽  
Sib Krishna Ghoshal ◽  
Rodziah Nazlan
Keyword(s):  
Electric Field Effect ◽  
Tellurite Glasses ◽  
Solid State Lasers ◽  
Absorption Bands ◽  
Precise Control ◽  
Amorphous Nature ◽  
Xrd Patterns ◽  
Inorganic Glasses ◽  
Rare Earth Doped

Enhancing the optical performance of rare earth doped binary inorganic glasses is an ever-demanding quest. Samarium (Sm3+) doped zinc tellurite glasses containing Manganese (Mn) nanoparticles (NPs) with composition (59-x)TeO2-20ZnCl2-10ZnO-10Li2O-1Sm2O3-(x)Mn3O4, where x = 0 to 0.06 mol% are prepared by melt quenching technique. The role played by Mn NPs in enhancing the optical behaviors are analyzed and discussed. The XRD patterns confirm the amorphous nature of the glass. The UV-Vis-NIR spectra reveal seven prominent absorption bands of Sm3+ ions. The photoluminescence spectra display four peaks corresponding to 4G5/2→6H5/2, 4G5/2 →6H7/2, 4G5/2→6H9/2 and 4G5/2 →6H11/2 transitions. An enhancement in the luminescence intensity is observed up to 0.05 mol% concentration of NPs and the intensity quenches beyond it. The enhancement is attributed to local electric field effect of NPs in the proximity of Sm3+ ion. Our results on improved optical response via precise control of NPs contents may be useful for the development of solid state lasers and amplifiers.

Surface composition of Pt-Rh alloys; The role of lattice vibrational entropy

1986 ◽  
Vol 178 (1-3) ◽  
pp. A678
Author(s):  
A.D. Van Langeveld ◽  
J.W. Niemantsverdriet
Keyword(s):  
Surface Composition ◽  
Vibrational Entropy

The Role of Solid State Lasers in Soft-X-Ray Projection Lithography

1993 ◽  
pp. 247-261
Author(s):  
W. T. Silfvast ◽  
M. C. Richardson ◽  
H. Bender ◽  
A. Hanzo ◽  
V. Yanovsky ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Lasers ◽  
X Ray ◽  
Projection Lithography ◽  
Ray Projection

scholarly journals Thermodynamics of the Atomic Distribution in Pt3Pd2, Pt2Pd3 and their Corresponding (111) Surfaces

2021 ◽  
Vol 74 ◽  
Author(s):  
Kyle Meerholz ◽  
David Santos-Carballal ◽  
Umberto Terranova ◽  
Anzel Falch ◽  
Cornelia G.C.E. van Sittert ◽  
...  
Keyword(s):  
Solid State ◽  
Bimetallic Catalysts ◽  
Computational Study ◽  
Interatomic Potentials ◽  
Site Occupation ◽  
Surface Energies ◽  
General Utility ◽  
Production Of Hydrogen ◽  
Surface Models ◽  
State Models

ABSTRACT In this study, we have developed solid-state models of platinum and palladium bimetallic catalysts, Pt3Pd2 and Pt2Pd3, which are rapidly thermally annealed at 800 °C. These models were constructed by determining all the unique atomic configurations in a 2x2x1 supercell, using the program Site-Occupation Disorder (SOD), and optimized with the General Utility Lattice Program (GULP) using Sutton-Chen interatomic potentials. Each catalyst had 101 unique bulk models that were developed into surface models, which were constructed using the two-region surface technique before the surface energies were determined. The planes and compositions with lowest surface energies were chosen as the representative models for the surface structure of the bimetallic catalysts. These representative models will now be used in a computational study of the HyS process for the production of hydrogen. Keywords: HyS process, platinum, palladium, solid-state, catalyst, Site-Occupation Disorder.

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