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Unveiling a Novel, Cation-Rich Compound in a High-Pressure Pb–Te Binary System

Year: 2019

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide Because of the common oxidation states of group IV elements (+2 or +4) and group VI elements (−2), 1:1 and 1:2 are two typical stoichiometries found in the IV–VI compounds. Particularly, in the Pb–Te binary system, the 1:1 stoichiometric PbTe is believed to be the only stable compound. Herein, using evolutionary algorithms, density functional theory, a laser-heated diamond anvil cell, and synchrotron X-ray diffraction experiments, we discovered a novel Pb–Te compound with an unexpected stoichiometry of 3:2 above 20 GPa. This tetragonal Pb 3 Te 2 is the one of the very few cation-rich compounds that has ever been discovered in the entire IV–VI binary system. Further analyses based on electron density distribution, electron localization function, and Bader charge have shown that this newly discovered compound has a mixed character of chemical bonding with a decreased ionicity. By further calculating the electron–phonon interaction, Pb 3 Te 2 is predicted to exhibit a superconducting transition at low temperatures. The discovery of Pb 3 Te 2 paves the way for further explorations of other novel cation-rich IV–VI group compounds.

Source: ACS Central Science

DOI: 10.1021/acscentsci.9b00083

Authors: Hulei Yu, Xiaohuan Lin, Kuo Li, Yue Chen

Institutions: University of Hong Kong, Center for High Pressure Science and Technology Advanced Research, Center for High Pressure Science & Technology Advanced Research

Language: English

Topic: High-pressure geophysics and materials

Subfield: Geophysics

Field: Earth and Planetary Sciences

Domain: Physical Sciences

Open Access status: diamond

Funders: National Natural Science Foundation of China, Research Grants Council, University Grants Committee