On the mechanism of the pressure-induced wurtzite- to NaCl-type phase transition in CdS: an X-ray diffraction study

The high-pressure behavior of wurtzite-type US up to the transition pressure of about 2.5 GPa was studied using single-crystal X-ray diffraction techniques. The fit of the Birch-Murnaghan equation of state gave a bulk modulus K = 62.8(8) GPa with a fixed pressure derivative K' = 4. During the phase transformation the single crystals were destroyed but the obtained material showed a pronounced preferred orientation. Therefore, orientation relations between the low-pressure wurtzite-type phase and the high-pressure NaCl-type phase could be determined. Apart from slight tilts with unknown origin between the unit cells of both structures, the observations support the usual transition mechanism. (C) 2004 Elsevier SAS. All rights reserved.