Spectroscopy at very high pressures—XXV: The IR spectrum of ferrocene at high pressures

The IR spectrum of ferrocene has been examined up to 50kbar under approximately hydrostatic conditions in a gasketed diamond anvil cell, and also under shear stress without gaskets. The results provide evidence in support of Duecker and Lippincott's claim of a phase transition at about 11.5 ± 0.5 kbar which is sluggish except under shear stress. Thermal strain and phonon self-energy contributions to the temperature-induced frequency shifts were analysed but no general pattern emerged.