English
Related papers

Related papers: Ga+, In+ and Tl+ Impurities in Alkali Halide Cryst…

200 papers

An ab initio study of the doping of alkali halide crystals (AX: A = Li, Na, K, Rb; X = F, Cl, Br, I) by ns2 anions (Ag- and Cu-) is presented. Large active clusters with 179 ions embedded in the surrounding crystalline lattice are…

Materials Science · Physics 2009-10-31 Andrés Aguado , José M. López , Julio A. Alonso

Ab initio Perturbed Ion cluster-in-the-lattice calculations of the impurity centers NaI:Tl+ and CsI:Tl+ are pressented. We study several active clusters of increasing complexity and show that the lattice relaxation around the Tl+ impurity…

Materials Science · Physics 2009-10-31 Andres Aguado , Andres Ayuela , Jose M. Lopez , Julio A. Alonso

We carried out numerical calculations by an extended-Hueckel program in order to check the analytical results reported in the preceding Part I and Part II. We typically consider alkali halide clusters composed of some tens of constituent…

The neutralization of low energy Na$^+$ and Li$^+$ ions scattered from Au nanoclusters formed by deposition onto oxide surfaces decreases as the cluster size increases. An explanation for this behavior is provided here, which is based on…

Mesoscale and Nanoscale Physics · Physics 2018-08-08 Christopher Salvo , Prasanta Karmakar , Jory Yarmoff

Alkali halide crystals doped with certain impurity ions show a low temperature behaviour, which differs significantly from that of pure crystals. The origin of these characteristic differences are tunneling centers formed by atomic or…

Disordered Systems and Neural Networks · Physics 2009-11-07 M. Thesen , R. Kühn , C. Enss , S. Ludwig

Extending earlier work on a vibronic theory of the FA centers in alkali halides, the reorientation is now considered of an off-center Li+ impurity, either isolated or near an F center. We derive analytically periodic potential energy…

Ab initio calculations using the Perturbed Ion model, with correlation contributions included, are presented for nonstoichiometric (NaI)_nNa+ and (CsI)_nCs+ (n=1-14) cluster ions. The ground state and several low-lying isomers are…

Atomic and Molecular Clusters · Physics 2009-10-31 A. Aguado , A. Ayuela , J. M. Lopez , J. A. Alonso

We report a laboratory measurement of how impurities shift Coulomb crystallization in a strongly interacting ionic system. This is achieved by using laser cooled Ca$^+$ crystals doped with a controlled number of Xe$^{12+}$ highly charged…

Other Condensed Matter · Physics 2026-03-17 Mingyao Xu , Aaron A. Smith , Leonid Prokhorov , Vera Guarrera , Giovanni Barontini

Tuning of the electronic properties of pre-synthesized colloidal semiconductor nanocrystals (NCs) by doping plays a key role in the prospect of implementing them in printed electronics devices such as transistors, and photodetectors. While…

Materials Science · Physics 2021-05-25 Yorai Amit , Yuanyuan Li , Anatoly I. Frenkel , Uri Banin

Ab initio perturbed ion plus polarization calculations are reported for doubly-charged nonstoichiometric (MgO)nMg2+ (n=1-29) cluster ions. We consider a large number of isomers with full relaxations of the geometries, and add the…

Atomic and Molecular Clusters · Physics 2009-10-31 Andres Aguado , Francisco Lopez-Gejo , Jose M. Lopez

The first--principles density functional molecular dynamics simulations have been carried out to investigate the geometric, the electronic, and the finite temperature properties of pure Li clusters (Li$_{10}$, Li$_{12}$) and Al--doped Li…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Mal--Soon Lee , S. Gowtham , Haiying He , Kah--Chun Lau , Lin Pan , D. G. Kanhere

The presence of first sharp diffraction peaks in the partial structure factors is investigated in computer simulations of molten mixtures of alkali halides. An intermediate range ordering appears for the Li+ ions only, which is associated…

Materials Science · Physics 2008-10-17 M. Salanne , C. Simon , P. Turq , P. A. Madden

A density functional theory is used to predict the binding energy of atomic and molecular impurities (Ne, Ar, Kr, Xe, Li, Na, K, Rb, Cs, and SF$_6$) in the center of $^4$He clusters, in the limit of zero temperature and for zero angular…

Condensed Matter · Physics 2009-10-22 F. Dalfovo

The structures and relative stabilities of doubly-charged nonstoichiometric (CaO)$_n$Ca$^{2+}$ (n=1--29) cluster ions and of neutral stoichiometric (MgO)$_n$ and (CaO)$_n$ (n=3,6,9,12,15,18) clusters are studied through {\em ab initio}…

Atomic and Molecular Clusters · Physics 2007-05-23 Andres Aguado , Jose M. Lopez

First-principles calculations have been performed to study the formation of defect complexes in Ti doped alpha-Al2O3 crystals. The formation energies of isolated Ti3+ and Ti4+ defects, pairs, triples and quadruples of Ti ions and Al…

Materials Science · Physics 2018-01-12 L. Yu. Kravchenko , D. V. Fil

We present a detailed investigation of static dipole polarizability of lithium clusters containing up to 22 atoms. We first build a database of lithium clusters by optimizing several candidate structures for the ground state geometry for…

Materials Science · Physics 2007-11-13 Rajendra R. Zope , Tunna Baruah , Mark R. Pederson

The experimental evidence of an anomalous behavior in the decay times of Tl$^+$-like impurity centers in alkali-halide crystals has generated a revival of interest with respect to these materials. We discuss here about the possibility that…

Materials Science · Physics 2014-03-06 D. Mugnai , G. P. Pazzi , P. Fabeni , A. Ranfagni

Abundance variations in moderately metal-rich globular clusters can give clues about the formation and chemical enrichment of globular clusters. CN, CH, Na, Mg and Al indices in spectra of 89 stars of the template metal-rich globular…

Astrophysics · Physics 2009-11-13 A. Alves-Brito , R. P. Schiavon , B. Castilho , B. Barbuy

We investigate the light-element behavior of red giant stars in Northern globular clusters (GCs) observed by the SDSS-III Apache Point Observatory Galactic Evolution Experiment (APOGEE). We derive abundances of nine elements (Fe, C, N, O,…

The stability of two-component clusters consisting of light (Na or K) and heavy (Rb or Cs) alkali atoms formed on helium nanodroplets is studied by femtosecond laser ionization in combination with mass spectrometry. Characteristic stability…

Atomic and Molecular Clusters · Physics 2011-12-19 G. Droppelmann , M. Mudrich , C. P. Schulz , F. Stienkemeier
‹ Prev 1 2 3 10 Next ›