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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Il nuovo cimento della Società Italiana di Fisica 1 (1982), S. 409-421 
    ISSN: 0392-6737
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Description / Table of Contents: Riassunto Questo lavoro analizza dati sperimentali di diffrazione neutronica da soluzioni liquide K−KCl e Rb−RbBr a varie composizioni. Mentre la diffusione a piccoli angoli (per numeri d'onda trasferiti inferiori a circa 1 Å−1) è fortemente influenzata da effetti di schermo e di aggregazione associati agli elettroni esterni della componente metallica, l'ordine a corto raggio in questi sistemi è ben riprodotto da un modello che li considera come miscele ioniche. La struttura del sistema K−KCl ad alte concentrazioni della componente metallica è ulteriormente studiata in dettaglio da punti di vista diversi. Si mostra cosí che il sistema in questa regione di composizione può anche essere visto come un metallo espanso di cui gli ioni alogeno riducono fortemente l'ordine a corto raggio. Si discutono infine alcuni aspetti dell'ordine a corto raggio nella regione di alte concentrazioni della componente salina, associati con uno struttura secondaria nella figura di diffrazione.
    Abstract: Резюме Исследуются результаты дифракции нейтронов на жидких растворах K−KCl и Rb−RbBr при различных составах. Исследование проводится в рамках модели ионной смеси, в которой пренебрегается экранированием и агрегацией, обусловленными металлическими электронами. Эта модель объясняет главные особенности наблюденных картин дифракции для волновых чиселk порядка 1 Å−1. С разных точек зрения анализируется фазовая диаграмма в системе K−KCl. Описываются короткодействующие корреляции для ионов калия в указанной области, используя металлический радиус, выведенный из свойств чистогожидкого металла, но простая металлическая модель должна быть дополнена предположением, что существенный беспорядок вводится в структуру металла ионами галогенов. Интерпретируются особенности короткодействующего упорядочения в области с высоким содержанием соли, которые связаны с выступом у главного пика со стороны большихk на диаграмме дифракции.
    Notes: Summary Neutron diffraction patterns from K−KCl and Rb−RbBr liquid solutions at various compositions are examined in a ionic-mixture model which neglects screening and aggregation due to the metallic electrons. The main features of the observed diffraction patterns for wave numberk roughly above 1 Å−1 are accounted for by the model. The approach to the metal-rich end of the phase diagram is analysed in detail from different viewpoints in the K−KCl system. Short-range correlations of the potassium ions are described in this region by a metallic radius deduced from properties of the pure liquid metal, but a simple expanded-metal model must be supplemented by the assumption that considerable disorder is introduced in its structure by the halogen ions. Features of short-range ordering in the salt-rich region that are implied by a shoulder on the high-k side of the main peak in the diffraction pattern are also commented upon.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Il nuovo cimento della Società Italiana di Fisica 3 (1984), S. 730-738 
    ISSN: 0392-6737
    Keywords: Studies of specific liquid structures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Description / Table of Contents: Riassunto Il lavoro discuta la struttura di soluzioni di cloruro di potassio in potassio liquido a concentrazionex=0.2, contrastando i risultati di un modello teorico con dati di diffrazione neutronica. Si esaminano, in particolare, lo schermo elettronico di fluttuazioni ioniche di grande lunghezza d'onda e la natura dell'ordine ionico a corto raggio. Si suggeriscono ulteriori esperimenti di diffrazione nella regione di piccoli angoli di diffusione e a concentrazioni maggiori della componente salina.
    Abstract: Резюме В рамках теотической модели, вклющей данные по дифракции нейтронов, исследуется структура Ъидких растворов K0.8-(KCl)0.2. Обсуждаются электронное зкранирование длинноволновых флуктуаций плотности ионов и природа коротковолоовой упорядоченности ионов. Предлагаются дифракционные эксперименты по малоугловому рассеянию и при более высоких концентрациях (KCl).
    Notes: Summary The structure of liquid solutions of potassium chloride in potassium, at a concentrationx=0.2 of the salt component, is examined in an electron-ion model against multipattern neutron diffraction data. Electronic screening of long-wave-length ionic-density fluctuations and the nature of short-range ionic order are discussed. Further diffraction experiments in the small-angle scattering region and at higher concentrations of the salt component are suggested.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Il nuovo cimento della Società Italiana di Fisica 3 (1984), S. 509-521 
    ISSN: 0392-6737
    Keywords: Localized single-particle electronic states (excluding impurities)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Description / Table of Contents: Riassunto Il lavoro presenta uno studio teorico di elettroni solvatati a forte diluizione in alogenuri alcalini fusi. Un calcolo autoconsistente dello stato fondamentale è confrontato con dati NMR d'interazioni iperfini e con misure di suscettività magnetica. Le bande di assorbimento ottico dovute a transizioni 1s→2p e 1s→3p sono calcolate in uno schema di Franck-Condon e i risultati sono confrontati con l'evidenza sperimentale, con attenzione particolare all'analisi dello spettro nel CsCl fuso data da Yuh e Nachtrieb. Si discutono quindi un'instabilità degli stati eccitati sotto rilassamento ionico, la vita media dello stato fondamentale nel liquido e lo spostamento dello spettro eccitonico dovuto all'elettrone solvatato.
    Abstract: Резюме Теоретически исследуются свойства сольватированных электронов при высокой степени разведения в четырех расплавленных щелочных галоидах. Самосогласованное вычисление основного состояния связанного электрона и окружающей жидкой структуры сравнивается с данными ЯМР для сверхтонких смещений и с измерениями магнитной восприимчивости. Вычисляются зоны поглощения, связанные с переходами 1s→2p и 1s→3p в схеме Франка-Кондона. Полученные результаты сравниваются с имеющимися экспериментальными данными по оптическому поглощению, причем, особое внимание уделяется анализу спектров для расплавленного CsCl. Также обсуждается неустойчивость возбужденных состояний относительно ионной релаксации и конечное время жизни основного состояния в жидкости. В заключение, оценивается смещение экситонного спектра, обусловленное сольватированным электроном.
    Notes: Summary Properties of solvated electrons at high dilution in four molten alkali halides are investigated theoretically. A self-consistent evaluation of the bound ground state of the electron and of the surrounding liquid structure, already developed in a previous paper, is compared with the results of NMR hyperfine shifts and magnetic-susceptibility measurements. The absorption bands associated with Franck-Condon 1s→2p and 1s→3p transitions are calculated and compared with the available data of optical absorption, with special emphasis on the detailed analysis by Yuh and Nachtrieb for molten CsCl. An instability of the excited states against ionic relaxation and the origin of a finite lifetime for the ground state are also discussed. Finally, the perturbation induced by the solvated electron in the fundamental absorption of the molten salt is estimated.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 83 (1985), S. 1232-1233 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The 1/Z expansion of the total energy E(Z,N) is compared with a recent result giving the total energy of heavy positive atomic ions in the weak ionization limit N/Z near to unity. The leading term in the asymptotic limit of the high order coefficients of the 1/Z expansion for large N is thereby determined precisely. The results are finally compared and contrasted with the treatment by Stillinger of the He-like series with N=2.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Physica B+C 111 (1981), S. 283-290 
    ISSN: 0378-4363
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Physica B+C 112 (1982), S. 360-364 
    ISSN: 0378-4363
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Journal of Physics and Chemistry of Solids 43 (1982), S. 1093-1097 
    ISSN: 0022-3697
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Physica B+C 124 (1984), S. 22-24 
    ISSN: 0378-4363
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Physica B+C 111 (1981), S. 11-23 
    ISSN: 0378-4363
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Physica A: Statistical Mechanics and its Applications 119 (1983), S. 356-368 
    ISSN: 0378-4371
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
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