Formation of a Polar Structure in the Metallic Niobium Sulfide Nb4S3

Autor:	Markus Ströbele, Carl P. Romao, Hans-Jürgen Meyer, Eric Dorsch, Fabian Grahlow
Rok vydání:	2021
Předmět:	chemistry.chemical_classification Electron density Sulfide Chemistry Fermi level Niobium chemistry.chemical_element Electron Sulfur Inorganic Chemistry symbols.namesake Electrical resistivity and conductivity Chemical physics symbols Density functional theory Physical and Theoretical Chemistry
Zdroj:	Inorganic Chemistry. 60:17669-17676
ISSN:	1520-510X 0020-1669
Popis:	The synthesis of Nb4S3, a previously undiscovered binary sulfide, was achieved using Nb3Br7S as a precursor. Its structure is composed of Nb6S triangular prisms arranged in a polar (Imm2) configuration, with sulfur atoms lying in channels along the a axis. Electrical resistivity measurements and density functional theory calculations were used to determine that Nb4S3 is metallic and therefore a polar metal, with metallic bands occupied by electrons with primarily niobium character. The electrons near the Fermi level are so closely associated with the niobium sublattice that the sulfur atoms have positive Born effective charges, indicating that the electrostatic interactions between sulfur atoms are unscreened. Calculations of the dependence of the electron density on the sulfur atomic positions confirm that the metallic electrons do not screen the dipole-dipole interactions between sulfur atoms, which allows polarity and metallicity to coexist in Nb4S3. These findings suggest that applied electric fields might be able to reverse the polarity of thin films of Nb4S3.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::da79adec4335792a0ead5354f5a8e316 https://doi.org/10.1021/acs.inorgchem.1c02263 Zobrazit plný text záznamu