Abstract

Experimental results are presented concerning the synthesis, crystal chemistry and electrical characterization of Pb–Sb–S sulfosalts, especially boulangerite, Pb5Sb4S11. The crystals were grown by sublimation or chemical vapor transport using NH4Cl or iodine as transporting agents. Owing to its rod-like structure, boulangerite typically appears as thin needles as well as fibers with diameters down to a few nanometers. Both ordered as well as disordered structures can be produced depending on growth temperature. In addition, depending on the temperature of deposition, Pb2Sb2S5 or halogen-bearing sulfosalts such as dadsonite or iodine-substituted pillaite can be prepared as well. By means of thermodynamic modeling, the chemical vapor-transport reaction of boulangerite is described, and an explanation for the formation of the halogen-containing compounds at lower temperatures of deposition is given. Within the homogeneity range of boulangerite Pb5−xSb4+xS11+x/2 with 0.35 ≥ x ≥ −0.09, the electrical conductivity σ reaches values between 10−8 and 10−3 Ω−1m−1. For Pb2Sb2S5, iodine-substituted pillaite and dadsonite, σ was determined to be 2.0(8) × 10−4, 5(2) × 10−4 and 7(3) × 10−4 Ω−1m−1, respectively.

You do not currently have access to this article.