CHEMICAL PHYSICS LETTERS, v.218, no.1-2, pp.107 - 114
Abstract
An orientational ordering transition was observed near 260 K from a C-70 film in a temperature-dependent Raman study. The 1183 cm(-1) Raman band shows a rather dramatic change in both frequency and bandwidth over the range of 220-280 K. The low-frequency Raman band at 260 cm(-1) disappears, and at its expense, a new band emerges at 266 cm(-1) as the temperature is decreased. The relatively smooth transition in temperature is attributed to the stacking disorder in molecular packing and the nonuniform orientational conformation of C-70 solid.