PRESSURE-INDUCED STRUCTURAL TRANSITIONS IN NANOMETER-SIZE PARTICLES OF PBS

At elevated pressure, PbS undergoes a first order phase transition fro m the NaCl or B1 structure to an orthorhombic structure. The effects o f particle sizes in the nanometer range on this transition have been i nvestigated using energy-dispersive x-ray diffraction of synchrotron p roduced wiggler radiation. Relative to the bulk crystals, the onset of transition pressure showed a significant increase with decreasing par ticle size. The results also show that compressibility increases with decreasing particle size: this increase is continuous through the phas e transition. (C) 1996 American Institute of Physics.