Prevalence of pretransition disordering in the rutile-to- CaCl 2 phase transition of GeO 2
- Univ. of Nevada, Las Vegas, NV (United States)
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Eidgenoessische Technische Hochschule (ETH), Zurich (Switzerland)
WE report the ability to tailor a material's electronic properties using density driven disordering has emerged as a powerful route to materials design. The observation of anomalous structural and electronic behavior in the rutile to CaCl2 phase transition in SnO2 led to the prediction that such behavior is inherent to all oxides experiencing such a phase transition sequence [Smith et al., J. Phys. Chem. Lett. 10, 5351 (2019)]. Here, the ultrawide band gap semiconductor GeO2 is confirmed to exhibit anomalous behavior during the rutile to CaCl2 phase transition. A phase pure rutile GeO2 sample synthesized under high-pressure, high-temperature conditions is probed using synchrotron diffraction and x-ray and optical spectroscopy under high pressure conditions. Density functional theory calculations show that the enthalpic barrier to displacing an oxygen along the B1g librational mode decreases with pressure leading up to the rutile to CaCl2 phase transition. The band structure of the distorted state shows that such oxygen displacements form small polarons.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States). Advanced Photon Source (APS); Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA); US Air Force Office of Scientific Research (AFOSR); USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities Division
- Grant/Contract Number:
- AC02-06CH11357; FA9550-21-1-0097; AC52-07NA27344
- OSTI ID:
- 1897902
- Alternate ID(s):
- OSTI ID: 1871784
- Report Number(s):
- LLNL-JRNL-836003; 171963; TRN: US2310842
- Journal Information:
- Physical Review. B, Vol. 104, Issue 13; ISSN 2469-9950
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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