Fluorides of Silver Under Large Compression** |
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| Authors: | Dr. Dominik Kurzydłowski Dr. Mariana Derzsi Prof. Eva Zurek Prof. Wojciech Grochala |
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| Affiliation: | 1. Faculty of Mathematics and Natural Sciences, Cardinal Stefan Wyszyński University Warsaw, Wóycickiego 1/3, 01-938 Warsaw, Poland;2. Advanced Technologies Research Institute, Faculty of Materials Science and Technology in Trnava, Slovak University of Technology in Bratislava, Jána Bottu 8857/25, 917-24 Trnava, Slovakia;3. Department of Chemistry, State University of New York at Buffalo, 777 Natural Sciences Complex, Buffalo, New York, 14260–3000 USA;4. Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland |
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| 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 Ag2+ cations (Ag3F4 and Ag2F3) are thermodynamically stable at ambient and low pressure. Both are computed to be magnetic semiconductors under ambient pressure conditions. For Ag2F5, containing both Ag2+ and Ag3+, 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. |
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| Keywords: | fluorides high pressure magnetic superexchange mixed-valent compounds phase transitions |
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