STRUCTURAL TRANSFORMATION IN PbS AND HgS NANOCRYSTALS UNDER HIGH PRESSURE

Abstract

The phase transition induced by pressure in the PbS and HgS nanocrystals was studied by in situ high pressure X-ray powder diffraction measurements. PbS underwent a phase transition from B1-B16 at 7 GPa whereas no transition was observed in HgS up to 15 GPa. The transition remained unaltered on the release of pressure. The volume decreased with an increase in pressure. There is a shift in transition pressure towards the higher side when compared with the bulk materials.

Pressure Induced Nanoparticle Phase Behavior, Property, and Applications

“…Reported phase transition pressures from the literature. The red circle marks the results obtained from the mechanical milled samples. , The blue region highlights the experiments conducted on the samples without use of a pressure transmitting medium (ref A, ref B, ref C, ref D, ref E, ref F).…”

Pressure Induced Assembly and Coalescence of Lead Chalcogenide Nanocrystals

“…Lead chalcogenide (PbX, X = S or Se) NCs possess broad absorption and narrow emission bands, together with large exciton Bohr radii, making them ideal candidates for different optoelectronic applications. − Even though several investigations have been carried out, − the high-pressure behaviors of lead chalcogenide NCs have not been thoroughly understood. For example, at atomic scale, high-pressure induced structural transformation from rock-salt (RS) to orthorhombic (OR) structures has been reported for lead chalcogenide NCs with different sizes ranging from 3 to 30 nm. − However, phase behaviors of those NCs with even smaller sizes are not well documented. On the other hand, pressure-induced assembly and coalescence have been demonstrated for ordered arrays of 3.5 nm spherical PbS NCs and 13 nm PbS nanocubes, but such morphological transformation under pressure for other lead chalcogenide NCs is still unknown.…”