Pressure‐induced Pb–Pb bonding and phase transition in Pb2SnO4
Stękiel, Michał
Zimmer, Dominik
Bayarjargal, Lkhamsuren
Bunk, Katja
Morgenroth, Wolfgang
Milman, Victor
Refson, Keith
Jochym, Dominik
Byrne, Peter J. P.
Winkler, Björn
DOI: https://doi.org/10.1107/S205252062001238X
Persistent URL: http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/8473
Zimmer, Dominik; 1Goethe University, Institute of Geosciences, Crystallography, Frankfurt, Germany
Bayarjargal, Lkhamsuren; 1Goethe University, Institute of Geosciences, Crystallography, Frankfurt, Germany
Bunk, Katja; 1Goethe University, Institute of Geosciences, Crystallography, Frankfurt, Germany
Morgenroth, Wolfgang; 1Goethe University, Institute of Geosciences, Crystallography, Frankfurt, Germany
Milman, Victor; 2Dassault Systèmes BIOVIA, Cambridge, United Kingdom
Refson, Keith; 3Royal Holloway, University of London, Physics, Oxford, United Kingdom
Jochym, Dominik; 4Scientific Computing Department, Rutherford Appleton Laboratory, Oxford, United Kingdom
Byrne, Peter J. P.; 5University of York, Physics, Heslington, United Kingdom
Winkler, Björn; 1Goethe University, Institute of Geosciences, Crystallography, Frankfurt, Germany
Abstract
High‐pressure single‐crystal to 20 GPa and powder diffraction measurements to 50 GPa, show that the structure of Pb2SnO4 strongly distorts on compression with an elongation of one axis. A structural phase transition occurs between 10 GPa and 12 GPa, with a change of space group from Pbam to Pnam. The resistivity decreases by more than six orders of magnitude when pressure is increased from ambient conditions to 50 GPa. This insulator‐to‐semiconductor transition is accompanied by a reversible appearance change from transparent to opaque. Density functional theory‐based calculations show that at ambient conditions the channels in the structure host the stereochemically‐active Pb 6s2 lone electron pairs. On compression the lone electron pairs form bonds between Pb2+ ions. Also provided is an assignment of irreducible representations to the experimentally observed Raman bands.
The structure of Pb2SnO4 is found to strongly distort on compression and a structural phase transition with a change of space group from Pbam to Pnam occurs at ∼11 GPa. Our complementary DFT‐based calculations show that at ambient conditions, the channels in the structure host the stereochemically active Pb 6s2 lone electron pairs which form bonds between the Pb2+ ions with increasing pressure. image
Subjects
lead stannate (Pb2SnO4)density functional theory
high‐pressure X‐ray diffraction
pressure‐induced phase transition
insulator–semiconductor transition