A HRTEM Study of Defects in Silver-Doped Galena

A. Pring and T. B. Williams*
Department of Mineralogy, South Australian Museum, North Terrace, Adelaide, South Australia 5000, Australia
C.S.I.R.O. Division of Materials Science and Technology, Locked Bag 33, Clayton, Victoria 3168, Australia
*Present address JASCO International Co. Ltd., 4-21 Sennin-cho 2-chome, Hachioji City 193, Japan

Abstract: Synthetic Ag-doped PbS samples were Ar ion beam milled and examined by HRTEM. The silver was found to aggregate in inclusions which have no crystallographic relationship to the PbS host, rather than forming crystallographic defects. The Ag2S inclusions are 500 Å in diameter or larger. The limit of Ag substitution into PbS in solid solution in the absence of Bi or Sb is less than 0.1 mol %. The ion beam milling process introduced a large number of small dislocations in both Ag-doped and pure PbS specimens. These dislocations are thought to be formed through coalescences of point defects.

Keywords: galena • silver • HRTEM • ion beam milling

Mineralogical Magazine; September 1994 v. 58; no. 392; p. 455-459; DOI: 10.1180/minmag.1994.058.392.10
© 1994, The Mineralogical Society
Mineralogical Society (www.minersoc.org)