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Related papers: Why do gallium clusters have a higher melting poin…

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Experiments and simulations have been performed to examine the finite-temperature behavior of Ga$_{17}{}^{+}$ and Ga$_{20}{}^{+}$ clusters. Specific heats and average collision cross sections have been measured as a function of temperature,…

Statistical Mechanics · Physics 2009-11-11 Sailaja Krishnamurty , S. Chacko , D. G. Kanhere , G. A. Breaux , C. M. Neal , M. F. Jarrold

First principle calculations have been performed to understand the experimentally observed size sensitive variations in the characteristics of heat capacities of gallium clusters [G. A. Breaux {\it et. al.} J. Am. Chem. Soc., {\bf 126},…

Materials Science · Physics 2007-05-23 Sailaja Krishnamurty , Kavita Joshi , Shahab Zorriasatein , D. G. Kanhere

Phase diagrams are the most reliable way of predicting phase changes in a system. In this work, we create the phase diagram of the Ga(20-x)Al(x)+ bimetallic cluster system, for which the monometallic clusters display greater-than- bulk…

Materials Science · Physics 2015-03-24 Udbhav Ojha , Nicola Gaston

Density--functional simulations have been performed on Na$_{55}$, Na$_{92}$ and Na$_{142}$ clusters in order to understand the experimentally observed melting properties [M. Schmidt \textit{et al.}, Nature (London) \textbf{393}, 238…

Atomic and Molecular Clusters · Physics 2007-05-23 S. Chacko , D. G. Kanhere , S. A. Blundell

Thermal stability properties and the melting-like transition of Na_n, n=13-147, clusters are studied through microcanonical molecular dynamics simulations. The metallic bonding in the sodium clusters is mimicked by a many-body Gupta…

Atomic and Molecular Clusters · Physics 2007-05-23 Juan A. Reyes-Nava , Ignacio L. Garzon , Marcela R. Beltran , Karo Michaelian

Employing first principles parallel tempering molecular dynamics in the microcanonical ensemble, we report the presence of a clear solid-liquid-like melting transition in Al20+ clusters, not found in experiments. The phase transition…

Materials Science · Physics 2015-06-23 Udbhav Ojha , Krista G. Steenbergen , Nicola Gaston

We study the temperature structure of the central part (r<18' ~0.7 h50**-1 Mpc) of the Coma cluster of galaxies using ASCA data. Two different analysis methods produce results in good agreement with each other and reveal the presence of…

Astrophysics · Physics 2015-06-24 R. Hank Donnelly , M. Markevitch , W. Forman , C. Jones , E. Churazov , M. Gilfanov

We study the possibility that a large fraction of the gas at temperatures of \~10^7 K in cooling flow clusters cools by heat conduction to lower temperatures, rather than by radiative cooling. We argue that this process, when incorporated…

Astrophysics · Physics 2009-11-10 Noam Soker , Elizabeth L. Blanton , Craig L. Sarazin

Experiments and computer simulations have shown that the melt-ing temperature of solid hydrogen drops with pressure above about 65 GPa, suggesting that a liquid state might exist at low temperatures. It has also been suggested that this low…

A novel experimental scheme has been developed in order to measure the heat capacity of mass selected clusters. It is based on controlled sticking of atoms on clusters. This allows one to construct the caloric curve, thus determining the…

Atomic and Molecular Clusters · Physics 2008-11-13 Fabien Chirot , Pierre Feiden , Sébastien Zamith , Pierre Labastie , Jean-Marc L'Hermite

We present a spectral analysis of cool and cooling gas in 45 cool-core clusters and groups of galaxies obtained from Reflection Grating Spectrometer (RGS) XMM-$Newton$ observations. The high-resolution spectra show FeXVII emission in many…

High Energy Astrophysical Phenomena · Physics 2019-02-20 Haonan Liu , Ciro Pinto , Andrew C. Fabian , Helen R. Russell , Jeremy S. Sanders

The gas temperature in the cores of many clusters of galaxies drops inward by about a factor of three or more within the central 100 kpc radius. The radiative cooling time drops over the same region from 5 or more Gyr down to below a few…

Astrophysics · Physics 2007-05-23 A. C. Fabian

The melting of Al clusters in the size range 49 <= N <= 62 has been studied using two model interatomic potentials. The results for the two models are significantly different. The glue potential exhibits a smooth relatively featureless heat…

Other Condensed Matter · Physics 2007-05-23 Eva G. Noya , Jonathan P. K. Doye , Florent Calvo

We report a combined experimental and theoretical study of the melting curve and the structural behavior of vanadium under extreme pressure and temperature. We performed powder x-ray diffraction experiments up to 120 GPa and 4000 K,…

Materials Science · Physics 2019-10-02 D. Errandonea , S. G. MacLeod , L. Burakovsky , D. Santamaria-Perez , J. E. Proctor , H. Cynn , M. Mezouar

We present a spherically symmetric model for the origin and evolution of the temperature profiles in the hot plasma filling galaxy groups and clusters. We find that the gas in clusters is generically not isothermal, and that the temperature…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Michael McCourt , Eliot Quataert , Ian J. Parrish

Difference in nucleation of Ge quantum dots during Ge deposition at low (< 600C) and high (> 600C) temperatures on the Si(001) surface is studied by high resolution scanning tunneling microscopy. Two process resulting in appearance of…

Materials Science · Physics 2012-05-11 V. A. Yuryev , L. V. Arapkina

There is mounting observational evidence from Chandra for strong interaction between keV gas and AGN in cooling flows. It is now widely accepted that the temperatures of cluster cores are maintained at a level of 1 keV and that the mass…

Astrophysics · Physics 2010-04-06 Mateusz Ruszkowski , Mitchell C. Begelman

Stellar density and bar strength should affect the temperatures of the cool (T ~ 20-30 K) dust component in the inner regions of galaxies, which implies that the ratio of temperatures in the circumnuclear regions to the disk should depend…

We investigate the interplay of particle number, N, and structural properties of selected clusters with N=12 up to N=562 by employing Gupta potentials parameterized for Aluminum and extensive Monte-Carlo simulations. Our analysis focuses on…

Materials Science · Physics 2015-05-14 A. Bagrets , R. Werner , F. Evers , G. Schneider , D. Schooss , P. Woelfle

A dimer of bound atoms cannot melt, only dissociate. Bulk metals show a well defined first order transition between their solid and liquid phases. The appearance of the melting transition is explored for increasing clusters sizes via the…

Atomic and Molecular Clusters · Physics 2009-11-10 Ralph Werner
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