Nanosecond Electron Microscopy of Electrically Triggered Material Dynamics

Materials with fast electrical responses (e.g. piezoelectric, ferroelectric, phase transitions, electrochemical, etc.) are critical for modern and next-generation electronics. These responses can be affected by complex nanoscopic dynamics, and visualizing them is important for understanding the rate-limiting steps and for improving the dynamic properties. While in-situ biasing in TEM provides the required spatial resolution, it has been difficult to capture dynamics faster than milliseconds, whereas many electronic material responses occur within nanoseconds.

Here, we introduce voltage-triggered ultrafast electron microscopy, which allows to image reversible, electrically stimulated dynamics with nanometer-nanosecond resolution [1,2]. We first applied this capability to addressing the electrical pulse switching mechanism of room temperature charge density waves in 1T-TaS₂ [1]. Diffraction was used to track the atomic structure dynamics, while imaging revealed heterogeneous strain dynamics. We found that two processes contribute to charge density wave melting on nanosecond scales: electrical heating and acoustic resonance. We anticipate that this microscopy approach will provide key insights into the mechanisms underlying the dynamic properties of a broad range of electronic materials.

[1] DB Durham & TE Gage et al. “Nanosecond Structural Dynamics during Electrical Melting of Charge Density Waves in 1T−TaS₂.” Phys. Rev. Lett. 132, 226201 (2024)
[2] TE Gage & DB Durham et al. “Nanosecond Electron Imaging of Transient Electric Fields and Material Response.” (Preprint) ArXiv:2306.01171 (2023)

This material is based upon work supported by the U.S. Department of Energy, Office of Science, for support of microelectronics research, under contract number DE-AC0206CH11357. Work performed at the Center for Nanoscale Materials, a U.S. Department of Energy Office of Science User Facility, was supported by the U.S. DOE, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.