Universal phase dynamics in VO ₂ switches revealed by ultrafast operando diffraction

Journal Article · Thu Jul 15 00:00:00 EDT 2021 · Science

DOI:https://doi.org/10.1126/science.abc0652· OSTI ID:1808239

Sood, Aditya ^[1]; Shen, Xiaozhe ^[2]; Shi, Yin ^[3]; Kumar, Suhas ^[4]; Park, Su Ji ^[2]; Zajac, Marc ^[5]; Sun, Yifei ^[6]; Chen, Long-Qing ^[3]; Ramanathan, Shriram ^[6]; Wang, Xijie ^[2]; Chueh, William C. ^[1]; Lindenberg, Aaron M. ^[7]

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1. Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA., Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA.
2. SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA.
3. Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802, USA.
4. Hewlett Packard Labs, Palo Alto, CA 94304, USA.
5. Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA.
6. School of Materials Engineering, Purdue University, West Lafayette, IN 47907, USA.
7. Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA., Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA., SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA.

Understanding the pathways and time scales underlying electrically driven insulator-metal transitions is crucial for uncovering the fundamental limits of device operation. Using stroboscopic electron diffraction, we perform synchronized time-resolved measurements of atomic motions and electronic transport in operating vanadium dioxide (VO ₂ ) switches. We discover an electrically triggered, isostructural state that forms transiently on microsecond time scales, which is shown by phase-field simulations to be stabilized by local heterogeneities and interfacial interactions between the equilibrium phases. This metastable phase is similar to that formed under photoexcitation within picoseconds, suggesting a universal transformation pathway. Our results establish electrical excitation as a route for uncovering nonequilibrium and metastable phases in correlated materials, opening avenues for engineering dynamical behavior in nanoelectronics.

• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-76SF00515; SC0020145
• OSTI ID: 1808239
• Alternate ID(s): OSTI ID: 1804489; OSTI ID: 1823597; OSTI ID: 1840034; OSTI ID: 1880833
• Journal Information: Science, Journal Name: Science Journal Issue: 6552 Vol. 373; ISSN 0036-8075
• Publisher: American Association for the Advancement of Science (AAAS)
• Country of Publication: United States
• Language: English