https://doi.org/10.1140/epjd/e2003-00149-x
Spectroscopic manifestations of phase changes in CaArn clusters: finite size effects
1
Laboratoire de Physique Quantique (UMR 5626, CNRS) , IRSAMC, Université
Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex, France
2
Laboratoire Francis Perrin (CNRS-URA-2453) ,
CEA/DRECAM/Service des Photons, Atomes et Molécules,
CEN Saclay, 91191 Gif-sur-Yvette Cedex, France
Corresponding author: a florent@irsamc.ups-tlse.fr
Received:
10
September
2002
Published online:
3
July
2003
The finite temperature optical spectroscopy of CaArn clusters in the range
is investigated using a Diatomics-In-Molecule (DIM)
Hamiltonian and classical parallel tempering Monte Carlo simulations. The
absorption spectrum is calculated in the vertical approximation at various
temperatures between 2 K and 50 K. Several typical situations are reported.
CaAr6 shows a strong thermal broadening and shift of the spectral lines,
possibly associated with isomerization. CaAr13 only shows some broadening.
CaAr37 exhibits features corresponding to coexisting
isomers at low temperature. Finally, the abrupt changes in
the absorption spectrum in CaAr146 at about 20 K are indicative of
surface diffusion.
PACS: 36.40.Mr – Spectroscopy and geometrical structure of clusters / 36.40.Ei – Phase transitions in clusters / 36.40.Vz – Optical properties of clusters
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2003
