CuxHgy: a puzzling compound

The Cu-Kg system has been re-examined focusing on the only intermediate pha se. Our results are: not in agreement with the accepted literature data: bo th decomposition temperature and composition have been discussed. The struc tural determination performed on a single crystal is already in progress an d, although it shows a trigonal cell, the reflection conditions seem to exc lude the diffraction symbol R, rejecting the space group of the structure C u7Hg6, R3m. The existence of a small compositional range of stability has b een pointed out. (C) 2001 Elsevier Science B.V. All rights reserved.