Solid-State Dealloying Enables Local Symmetry Breaking in Ternary Intermetallic Thin Films
Abstract
Metastable quantum materials often occupy narrow composition windows with local symmetries distinct from competing equilibrium structures. These features open pathways for realizing qualitatively new electronic properties within a similar chemical subspace while at the same time complicating their deterministic synthesis. Here we illustrate a post-growth solid-state dealloying process using epitaxial ternary thin films in the La--Ag--Ge chemical space to realize a diffraction-averaged centrosymmetric superconducting structure. The process converts polar P63mc-LaAgGe into diffraction-averaged centrosymmetric AlB2-type P6/mmm La-Ag-Ge through net Ag loss during annealing at 800--900 ∘C. Atomic-resolution electron microscopy reveals local Ag--Ge displacements of both signs relative to the planar configuration, consistent with local inversion-symmetry-breaking distortions. The converted films exhibit composition-dependent superconductivity with critical temperatures below 1 K and in-plane upper critical fields that exceed the weak-coupling Pauli-field estimate by a factor of approximately 6 in the thinnest superconducting films. These results establish epitaxial solid-state dealloying as a route to phase-selective synthesis of metastable phases, offering control over atomic-scale structural configurations and their interplay with emergent electronic properties.
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BibTeX
@misc{ohno2026solidstate,
title = {{Solid-State Dealloying Enables Local Symmetry Breaking in Ternary Intermetallic Thin Films}},
author = {Mizuki Ohno and Reiley Dorrian and Veronica Show and Salva Salmani-Rezaie and Joseph Falson},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.28249},
eprint = {2609.28249},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.28249},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Solid-State Dealloying Enables Local Symmetry Breaking in Ternary Intermetallic Thin Films
AU - Mizuki Ohno
AU - Reiley Dorrian
AU - Veronica Show
AU - Salva Salmani-Rezaie
AU - Joseph Falson
PY - 2026
DA - 2026/09/23
PB - arXiv
DO - 10.48550/arxiv.2609.28249
UR - https://arxiv.org/abs/2609.28249
AB - Metastable quantum materials often occupy narrow composition windows with local symmetries distinct from competing equilibrium structures. These features open pathways for realizing qualitatively new electronic properties within a similar chemical subspace while at the same time complicating their deterministic synthesis. Here we illustrate a post-growth solid-state dealloying process using epitaxial ternary thin films in the La--Ag--Ge chemical space to realize a diffraction-averaged centrosymmetric superconducting structure. The process converts polar P6_3mc-LaAgGe into diffraction-averaged centrosymmetric AlB_2-type P6/mmm La-Ag-Ge through net Ag loss during annealing at 800--900 ^∘C. Atomic-resolution electron microscopy reveals local Ag--Ge displacements of both signs relative to the planar configuration, consistent with local inversion-symmetry-breaking distortions. The converted films exhibit composition-dependent superconductivity with critical temperatures below 1 K and in-plane upper critical fields that exceed the weak-coupling Pauli-field estimate by a factor of approximately 6 in the thinnest superconducting films. These results establish epitaxial solid-state dealloying as a route to phase-selective synthesis of metastable phases, offering control over atomic-scale structural configurations and their interplay with emergent electronic properties.
ER -