Vibrational spectroscopy at high pressures.

A review of high pressure work is presented with over 100 references spanning the period from October 1976 to March 1979. A full discussion is given of the history of Diamond Anvil Cell (DAC) design. Two new designs of DAC are tested, as are two different types of diamond anvil. Pressures in excess of 0.25 Megabars have been generated, and a study of benzene has been undertaken to test one of the new cells. Mid and far infrared spectra of ferrocene were recorded and compared with existing data on the solid state properties of this material. Raman and far infrared spectra of K2PtCI6 and K2ReCI6 at various temperatures and pressures have been obtained, and with thermal expansion and compressibility data, an attempt to relate the frequency shifts to anharmonic parameters has been performed. This study was extended to cover the pressure dependence of a further ten compounds of the form A2MX6. The phase behaviour of calcite (CaCO3) has been examined using mid and far infrared spectroscopy to 40 kbar, and the data analysed in conjunction with the results of Fong and Nicol. The effect of pressure and hence spin state on the far infrared spectra of some complexes of the form Fe phen2X2 has been studied.