INELASTIC-NEUTRON-SCATTERING STUDIES OF A QUASI-ONE-DIMENSIONAL CHARGE-DENSITY-WAVE SYSTEM - CHARACTERIZATION OF INTERCHAIN INTERACTIONS

The low-frequency part of the phonon spectrum of perdeuterated-[Pt(en) (2)][Pt(en)(2)I-2](ClO4)(4) (where en = 1,2-diaminoethane) has been me asured by inelastic neutron scattering. Longitudinal optical branches quasi-parallel to the acoustic ones are observed along the [xi 00] and [0 xi 0] directions, revealing the existence of a weak coupling of th e PtI charge-density-wave chains with their environment. The whole dat a, obtained in the (a,b*) reciprocal plane, are well described by a t wo-dimensional model that allowed the determination of the coupling co nstant and gaps for thr q=0 wave vector. The linear temperature depend ence of the phonon energies indicates an increase in interchain intera ctions on cooling. [S0163-1829(98)04329-X].