ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
We have investigated the phase diagrams of the alkali cyanides NaCN, KCN, RbCn, and CsCN in the pressure range up to 27 GPa, using the Raman and energy-dispersive x-ray techniques. We completed the information concerning the concept of a general phase diagram of the alkali cyanides with our measurements. In the case of KCN and RbCN we found at room temperature the expected high pressure phase. This phase IV, with a monoclinic structure (space group Cm) can be followed up to about 27 GPa. A different behavior was observed for NaCN. This crystal has in the pressure range between 10–15 GPa a coexistence region between the antiferro-ordered orthorhombic phase B and the ferro-ordered monoclinic phase. However, this monoclinic phase IVa in NaCN has a different structure with space group Pm (C1s). Finally the combination of the x-ray and Raman data allowed the determination of the structure of CsCN at low temperature and at high pressures. The structure is rhombohedral with space group R3m (phase VII).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.449289
