Relationship between atomic and electronic structure in Ln-bearing oxides

Journal Article · Wed Oct 15 00:00:00 UTC 2025 · Physical Review Materials

DOI: https://doi.org/10.1103/kttx-qmtd · OSTI ID:3001297

Uberuaga, Blas Pedro  ^[1]; Kocevski, Vancho  ^[1]; Talapatra, Anjana Anu  ^[1]; Derby, Benjamin Kyle  ^[1]; Kennedy, Ellis Rae  ^[1]

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1. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

Metastable states of matter are of great interest as they offer the promise of novel functionality. They are often a natural consequence of exposure to nonequilibrium environments. In oxides, metastability can take the form of new polymorphs, chemical disorder, and even amorphization. While significant attention has been given to the impact those changes have on the atomic properties of the material, the corresponding changes in the electronic structure have received less attention. Here, using density functional theory, we consider how the electronic structure varies with potential metastable structures in two classes of lanthanide-bearing oxides—pyrochlores and interlanthanide sesquioxides. We find that the changes depend strongly on both the crystal structure and crystal chemistry of the compound with, for example, disordering and amorphization either increasing or decreasing the bandgap depending on the chemistry. For the 𝐴₂⁢𝐵₂⁢O₇ pyrochlores, we find different dependencies of the bandgap on the 𝐴 = 𝐿⁢𝑛 cations as the 𝐵 cation is changed, which we relate to the nature of the density of states at the conduction band minimum for different 𝐵 chemistries. Our calculations are validated by electron energy loss spectroscopy measurements for two pyrochlore compounds in which amorphization does reduce the bandgap, consistent with our calculations on these two compounds. In conclusion, our results highlight the relationship between atomic and electronic structure and how radiation can be used to modify and potentially control the electronic properties of oxides.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE)
• Grant/Contract Number: 89233218CNA000001; AC02-05CH11231
• OSTI ID: 3001297
• Report Number(s): LA-UR--25-21102; 10.1103/kttx-qmtd
• Journal Information: Physical Review Materials, Journal Name: Physical Review Materials Journal Issue: 10 Vol. 9; ISSN 2475-9953
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English