Orthogonal Perturbations Resolve a Robust High-Frequency Relaxation in Nanocrystal-Derived Ag₄Zr₃S₈ Assemblies
Year: 2026
Type: preprint
Abstract: Nanocrystal (NC)-derived ion-conducting solids combine compositionally tunable nanoscale building blocks with dense networks of particle–particle and electrode contacts, making it difficult to distinguish material-associated relaxation dynamics from assembly-dependent impedance. Here, colloidally synthesized Ag₄Zr₃S₈ NCs are consolidated into pellets and interrogated by pressure- and temperature-resolved electrochemical impedance spectroscopy using Ag + -blocking (Au) and Ag + non-blocking (Ag) contacts. An objective discontinuity criterion is used to identify a continuous high-frequency analysis window, which is evaluated by Bayesian Hilbert-transform diagnostics and distribution-of-relaxation-times (DRT) analysis. Across 0.43–8.67 MPa and 298–393 K, Au-contacted pellets exhibit a dominant sample-associated relaxation centered near tau ~ 10⁻⁶ s. The dominant mode remains within the microsecond relaxation-time regime across the investigated pressure and temperature ranges, while both its characteristic time and spectral weight vary non-monotonically with the applied perturbation. The same fast response persists after changing Au to Ag contacts and pellet preparation history, whereas slower DRT features are more configuration-sensitive. A frequency-matched dummy-cell control exhibits its principal relaxation approximately one decade later in time. These results demonstrate how orthogonal mechanical, thermal, electrode, and assembly perturbations can distinguish sample-associated relaxation dynamics from configuration-sensitive impedance in NC-derived chalcogenide solids.
Source: ChemRxiv
Institution: Loyola University Chicago
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7220981632