Grzelak Adam, Derzsi Mariana, Grochala Wojciech
Center of New Technologies, University of Warsaw, Banacha 2C, 02-097 Warsaw, Poland.
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.
Inorg Chem. 2021 Feb 1;60(3):1561-1570. doi: 10.1021/acs.inorgchem.0c02970. Epub 2021 Jan 19.
We report a computational survey of chemical doping of silver(II) fluoride, which has recently attracted attention as an analogue of LaCuO-a known precursor of high-temperature superconductors. By introducing fluorine defects (vacancies or interstitial adatoms) into the crystal structure, we obtain nonstoichiometric, electron- and hole-doped polymorphs of AgF. We find that the ground-state solutions show a strong tendency for localization of defects and of the associated electronic states, and the resulting doped phases exhibit insulating or semiconducting properties. Furthermore, the distribution of Ag(I)/Ag(III) sites which appear in the crystal structure points to the propensity of the AgF system for phase separation upon chemical doping, which is in line with observations from previous experimental attempts. Overall, our results indicate that chemical modification may not be a feasible way to achieve doping in bulk silver(II) fluoride, which is considered essential for the emergence of high- superconductivity.
我们报告了一项关于氟化银（II）化学掺杂的计算研究，氟化银（II）作为高温超导体的已知前驱体LaCuO的类似物，最近受到了关注。通过将氟缺陷（空位或间隙吸附原子）引入晶体结构，我们获得了非化学计量的、电子和空穴掺杂的AgF多晶型物。我们发现基态解显示出缺陷及其相关电子态强烈的局域化趋势，并且所得的掺杂相表现出绝缘或半导体性质。此外，晶体结构中出现的Ag（I）/Ag（III）位点的分布表明，AgF系统在化学掺杂时倾向于相分离，这与先前实验尝试的观察结果一致。总体而言，我们的结果表明，化学修饰可能不是在块状氟化银（II）中实现掺杂的可行方法，而掺杂被认为是高温超导出现的关键。
