Domain nucleation across the metal-insulator transition of self-strained V 2 O 3 films
- Brookhaven National Laboratory (BNL), Upton, NY (United States)
- Helmholtz-Zentrum Berlin (HZB), (Germany). German Research Centre for Materials and Energy
- Technion-Israel Institute of Technology, Haifa (Israel)
- Univ. of Denver, CO (United States)
- Complutense Univ. of Madrid (Spain)
- Helmholtz-Zentrum Berlin (HZB), (Germany). German Research Centre for Materials and Energy; Fritz Haber Institute of the Max Planck Society, Berlin (Germany)
- Univ. of California, San Diego, La Jolla, CA (United States)
- Univ. of Oviedo (Spain)
Bulk V2O3 features concomitant metal-insulator (MIT) and structural (SPT) phase transitions at TC ~ 160 K. In thin films, where the substrate clamping can impose geometrical restrictions on the SPT, the epitaxial relation between the V2O3 film and substrate can have a profound effect on the MIT. Here we present a detailed characterization of domain nucleation and growth across the MIT in (001)-oriented V2O3 films grown on sapphire. By combining scanning electron transmission microscopy (STEM) and photoelectron emission microscopy (PEEM), we imaged the MIT with planar and vertical resolution. We observed that upon cooling, insulating domains nucleate at the top of the film, where strain is lowest, and expand downwards and laterally. This growth is arrested at a critical thickness of 50 nm from the substrate interface, leaving a persistent bottom metallic layer. As a result, the MIT cannot take place in the interior of films below this critical thickness. However, PEEM measurements revealed that insulating domains can still form on a very thin superficial layer at the top interface. Our results demonstrate the intricate spatial complexity of the MIT in clamped V2O3, especially the strain-induced large variations along the c axis. Finally, engineering the thickness-dependent MIT can provide an unconventional way to build out-of-plane geometry devices by using the persistent bottom metal layer as a native electrode.
- Research Organization:
- Brookhaven National Laboratory (BNL), Upton, NY (United States); Energy Frontier Research Centers (EFRC) (United States). Quantum Materials for Energy Efficient Neuromorphic Computing (Q-MEEN-C)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE); European Union (EU)
- Grant/Contract Number:
- SC0012704; SC0019273
- OSTI ID:
- 2340730
- Alternate ID(s):
- OSTI ID: 2473914
- Report Number(s):
- BNL--225554-2024-JAAM
- Journal Information:
- Physical Review Materials, Journal Name: Physical Review Materials Journal Issue: 3 Vol. 8; ISSN 2475-9953
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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