TY  - JOUR
AU  - Faka, Vasiliki
AU  - Lange, Martin A.
AU  - Daisenberger, Dominik
AU  - Böger, Thorben
AU  - Martinez de Irujo-Labalde, Xabier
AU  - Fallon, M. Jewels
AU  - Kieslich, Gregor
AU  - Zeier, Wolfgang G.
TI  - Solid Ion Conductors under Pressure: In Situ Monitoring of the Tetragonal to Cubic Phase Transition of $Na_3SbS_4$ and $Na_3PS_4$
JO  - ACS materials letters
VL  - 7
SN  - 2639-4979
CY  - Washington, DC
PB  - ACS Publications
M1  - FZJ-2025-02909
SP  - 2648 - 2654
PY  - 2025
AB  - The $Na_3PnS_4 (Pn = P, Sb)$ solid electrolytes are promising candidates for sodium solid-state batteries due to their potential high ionic conductivities. Structural modifications of these materials can induce a tetragonal-to-cubic phase transition, either by increasing temperature or by aliovalent substitutions. In this study, we introduce pressure as an alternative approach to observe the tetragonal-to-cubic phase transition in these materials. In situ synchrotron high-pressure powder X-ray diffraction shows a tetragonal-to-cubic phase transition at pressures of 2.9 GPa for $Na_3SbS_4$ and 14.6 GPa for $Na_3PS_4$. Rietveld refinements and symmetry analysis provide insights into the displacive phase transition mechanism related to the motion of $Na^+$ and the rotation of the $SbS_4^{3–}$ tetrahedra. Density functional theory calculations confirm that the cubic phase becomes thermodynamically favorable under high pressure compared to the tetragonal phase. These findings highlight the importance of high-pressure considerations in tailoring the properties of ionic conductors, an area that remains underexplored.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:001518534500001
DO  - DOI:10.1021/acsmaterialslett.5c00593
UR  - https://juser.fz-juelich.de/record/1043533
ER  -