Revealing the origin of ionic conduction in silver-iodide-doped silver phosphate glass
Abstract
Fast ionic transport is a defining feature of many solid electrolytes, yet its microscopic origin is not fully understood. In the absence of microscopic insights, the development of next-generation solid-state batteries remains largely empirical. Most existing measurements access either the low-frequency transport response or the high-frequency bound polarization, yet the intermediate mesoscopic frequency regime is where ionic transport emerges. By varying the AgI concentration (x) and performing time-domain terahertz spectroscopy (TDTS) in a prototypical glassy electrolyte (AgI)x(AgPO3)(1−x), we reveal this intermediate frequency regime and identify a crossover from bound-current-dominated conduction to conductivity arising from short-range dispersive ionic transport. We find that bound polarization associated with the bond-bending motion of the P−O- −Ag+ motif is present across compositions but is insufficient to produce ionic transport on its own. Transport emerges only when this polarization is embedded in a sufficiently soft AgPO3 glassy matrix and accompanied by a high carrier density. These ingredients together take the system from a vibrationally bound response to short-range dispersive motion.
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BibTeX
@misc{freedberg2026revealing,
title = {{Revealing the origin of ionic conduction in silver-iodide-doped silver phosphate glass}},
author = {Jennifer Freedberg and Joseph Maduzia and Andias Santoso and Ranveer Singh and Placid Ferreira and Fahad Mahmood},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.06738},
eprint = {2609.06738},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.06738},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Revealing the origin of ionic conduction in silver-iodide-doped silver phosphate glass
AU - Jennifer Freedberg
AU - Joseph Maduzia
AU - Andias Santoso
AU - Ranveer Singh
AU - Placid Ferreira
AU - Fahad Mahmood
PY - 2026
DA - 2026/09/06
PB - arXiv
DO - 10.48550/arxiv.2609.06738
UR - https://arxiv.org/abs/2609.06738
AB - Fast ionic transport is a defining feature of many solid electrolytes, yet its microscopic origin is not fully understood. In the absence of microscopic insights, the development of next-generation solid-state batteries remains largely empirical. Most existing measurements access either the low-frequency transport response or the high-frequency bound polarization, yet the intermediate mesoscopic frequency regime is where ionic transport emerges. By varying the AgI concentration (x) and performing time-domain terahertz spectroscopy (TDTS) in a prototypical glassy electrolyte (AgI)_x(AgPO_3)_(1−x), we reveal this intermediate frequency regime and identify a crossover from bound-current-dominated conduction to conductivity arising from short-range dispersive ionic transport. We find that bound polarization associated with the bond-bending motion of the P−O^- −Ag^+ motif is present across compositions but is insufficient to produce ionic transport on its own. Transport emerges only when this polarization is embedded in a sufficiently soft AgPO_3 glassy matrix and accompanied by a high carrier density. These ingredients together take the system from a vibrationally bound response to short-range dispersive motion.
ER -