You are here: Home :: Area NEM :: Chemistry :: Physical chemistry

Melanie Schnell, C. Herwig, J. A. Becker

Analysis of Semiconductor Cluster Beam Polarization Taking Small Permanent Dipole Moments into Account

Deflections of semiconductor cluster beams in an inhomogeneous electric field deliver enhanced polarizabilities for cold isolated Ga_NAs_M clusters with odd number of atoms n=N+M up to n=17. One speculated that the high polarizabilities result from their electronic open shell structure. This was qualitatively confirmed by optical absorption cross section measurements, but the enhancement of polarizability is too large to be explained through a Kramers–Kronig-relation as purely electronic effect. Moreover, quantum chemical calculations gave permanent dipole moments of some tenths of a Debye for certain compositions. The clusters are too heavy to identify these dipole moments by beam broadening effects, but we will show in the present analytic investigation within classical top theory, that a slight reversible-adiabatic alignment of the clusters dipole moment in the electric field increases the average beam deflection and the derived polarizability values. This effect was up to now not taken into account and it offers a consistent explanation of the Ga_NAs_M polarizabilities by small permanent dipole moments of some tenths of a Debye and a reasonable rotational temperature between 2 and 12K.

Zeitschrift für Physikalische Chemie, Oldenbourg Wissenschaftsverlag

Print ISSN: 0942-9352
Volume: 217, 08/2003
Pages: 1003

Journal homepage (external site)

Show all available items of this journal

 

Area NEM