Observation of Giant Kohn Anomaly in the One-Dimensional Conductor K2Pt(CN)4Br0.3· 3H2O

Abstract
Longitudinal acoustic phonons have been measured by coherent inelastic neutron scattering in the direction of the platinum chains of a single crystal of the one-dimensional conductor K2Pt(CN)4 Br0.3·3H2O at room temperature. The phonon dispersion curve shows a pronounced anomaly at the phonon wave number q0=0.32 Å1 and is interpreted as the logarithmic Kohn anomaly characteristic of a one-dimensional metal.