High-pressure single-crystal synchrotron X-ray diffraction study of lillianite

Abstract

In the present paper, high pressure data from a synchrotron X-ray diffraction study on a lillianite (Pb3Bi2S6) single crystal up to approximately 21 GPa are presented.A phase transition from lillianite (Bbmm space group #63, LP lillianite) to the high-pressure form β-Pb3Bi2S6 (Pbnm space group, HP lillianite) was confirmed and bracketed between 4.90 and 4.92 GPa.The transition is reversible but of first-order with a hysteresis of ~2.8 GPa. The phase transition to β-Pb3Bi2S6 showed weak effects of pseudomerohedral twinning that disappeared upon decompression, testifying to a full recovery of the single crystal of lillianite. This makes lillianite an interesting shapememory material.With a bulk modulus K4.9 = 78(3) GPa and K' = 5.1(4), β-Pb3Bi2S6 is markedly less compressibile than lillianite [K0 = 44(2) GPa, K' = 7( 1)]. Compressional anisotropy increased markedly in β-Pb3Bi2S6 with compressibility along the b axis [M0b = 130(6) GPa and M'b = 19(3) in lillianite, M4.9b = 145( 4) GPa and This is the peer-reviewed, final accepted version for American Mineralogist, published by the Mineralogical Society of America.The published version is subject to change. Cite as Authors (Year) Title. American Mineralogist, in press.

The High-Pressure Phase Transition in Jamesonite: A Single-Crystal Synchrotron X-ray Diffraction Study

“…At 9.7 GPa, a change in the structural evolution and a phase transition to β-jamesonite occurs, which has a much more rigid behavior [K 9.7 = 74(2) GPa, K' = 4] with respect to the α polymorph [K 0 = 36(1) GPa, K' = 5.7 (7)], as also reflected in the increased bulk moduli of Sb, Pb and Fe polyhedra in the β polymorph. A similar behavior was observed in lillianite [25], for which the authors measured K 0 = 44(2) GPa and K' = 7(1) for lillianite, and K 4.9 = 67(3) GPa and K' = 5.1(4) for its high-pressure polymorph β-Pb 3 Bi 2 S 6 .…”

“…. Bulk moduli (K0) vs. their pressure derivative (K') for different sulfosalts taken from [17,24,25,34,[36][37][38][39].…”

“…Satisfactory crystal structure refinements of α-and β-jamesonite were performed, and the results pointed out, on the one hand, a significant change in the orientation of Sb lone electron pairs upon the phase transition, in accordance with the change in symmetry, Figure 12. Bulk moduli (K 0 ) vs. their pressure derivative (K') for different sulfosalts taken from [17,24,25,34,[36][37][38][39].…”

“…High-pressure studies of selected sulfosalts such as heyrovskyite Pb 6 Bi 2 S 9 [24], lillianite Pb 3 Bi 2 S 6 [25] and chalcostibite CuSbS 2 [17] evidenced the occurrence of pressureinduced phase transitions, and these physical parameters could play a key role in the structural properties of these thermoelectric compounds.…”

Lone-Pair-Driven Structure Dimensionality: the Way to Ultralow Thermal Conductivity in PbmBi2S3+m Sulfides

“…The sulfide Pb 3 Bi 2 S 6 , m = 3 member of the series, exhibits several structural forms depending on the pressure. − The structures of all these forms differ only from the other by order–disorder distributions of the Pb 2+ and the Bi 3+ cations and will not be detailed here. They were previously described similarly to PbBi 2 S 4 , as chains of strongly distorted edge-sharing polyhedrons (Figure S17).…”