BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:The origin of anomalously high melting temperatures in gallium clu
 sters - Nicola Gaston\, University of Auckland
DTSTART:20160629T130000Z
DTEND:20160629T140000Z
UID:TALK66673@talks.cam.ac.uk
CONTACT:Lisa Masters
DESCRIPTION:Small clusters of gallium at sizes ranging from 17 to 85 atoms
  have been experimentally shown to melt at temperatures hundreds of Kelvin
  higher than the bulk metal [1]\, in contravention of the usual parading o
 f melting point depression.  On the other hand\, the low melting temperatu
 re of bulk gallium remains a poorly understood phenomena\, with contradict
 ory analyses of the liquid state complicating our understanding.\nIn our p
 revious work [2] we have demonstrated the ability of density functional th
 eory calculations to reproduce the experimental findings\, in particular t
 he strong size-sensitivity of the melting temperatures. We have also discu
 ssed in depth the rich potential energy landscape of the clusters\, in par
 ticular the transitions between different structural classes [3].\nIn this
  work we have analysed the liquid state of the clusters\, and found that i
 n contrast to the usual expectations of spherical drop-like behaviour\, th
 e clusters are distorted trivially for large proportions of the simulation
  time. The shortest axis of the clusters remains consistently at a length 
 suggestive of a bilayer structure\, albeit one in which the individual ato
 ms retain significant mobility in the two dimensional plane. These results
  explain the higher melting temperatures of the clusters as being due to l
 owered\nentropy of the liquid phase at small sizes [4]\, and give insight 
 into important questions yet to be asked about the nature of the bulk liqu
 id.\n\n[1] G. A. Breaux\, B. Cao\, and M. F. Jarrold. J. Phys. Chem. B\, 1
 09 \, 16575–16578\, 2005\; G. Breaux\,\nR. Benirschke\, T. Sugai\, B. Ki
 nnear\, and M. Jarrold. Phys. Rev. Lett.\, 91 \, 215508\, 2003.\n[2] K. G.
  Steenbergen and N. Gaston. Phys. Rev. B\, 88 \, 161402\, 2013\; K. G. Ste
 enbergen and N. Gaston.\nPhys. Chem. Chem. Phys.\, 15 \, 15325\, 2013\; K.
  G. Steenbergen\, D. Schebarchov\, and N. Gaston. J. Chem.\nPhys.\, 137 \,
  144307\, 2012.\n[3] K. G. Steenbergen and N. Gaston. Chem. - Eur. J. 21 \
 , 2862–2869\, 2015.\n[4] K. G. Steenbergen and N. Gaston. Nano Lett.\, 1
 6 \, 21\, 2016.
LOCATION:Todd Hamied Room\,  Department of Chemistry
END:VEVENT
END:VCALENDAR