Fluorides of Silver Under Large Compression. Issue 17 (25th February 2021)

• Record Type: Journal Article
• Authors: Kurzydłowski, Dominik; Derzsi, Mariana; Zurek, Eva; Grochala, Wojciech
• Is Part Of: Chemistry. Volume 27:Issue 17(2021)
• Page Start: 5536
• Page End: 5545
• Publication Date: 2021-02-25
• Subjects: fluorides -- high pressure -- magnetic superexchange -- mixed-valent compounds -- phase transitions; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202100028
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: The silver‐fluorine phase diagram has been scrutinized as a function of external pressure using theoretical methods. Our results indicate that two novel stoichiometries containing Ag + and Ag 2+ cations (Ag3 F4 and Ag2 F3 ) are thermodynamically stable at ambient and low pressure. Both are computed to be magnetic semiconductors under ambient pressure conditions. For Ag2 F5, containing both Ag 2+ and Ag 3+, we find that strong 1D antiferromagnetic coupling is retained throughout the pressure‐induced phase transition sequence up to 65 GPa. Our calculations show that throughout the entire pressure range of their stability the mixed‐valence fluorides preserve a finite band gap at the Fermi level. We also confirm the possibility of synthesizing AgF4 as a paramagnetic compound at high pressure. Our results indicate that this compound is metallic in its thermodynamic stability region. Finally, we present general considerations on the thermodynamic stability of mixed‐valence compounds of silver at high pressure. Abstract : Under pressure : New mixed‐valent fluorides of silver, as well novel structures of known compounds, are predicted to form in the Ag/F2 system at pressures exceeding 1 GPa.