Materials Science Research Lecture
***Refreshments at 3:45pm in Noyes lobby
Abstract:
This presentation will describe our recent results utilizing energy filtered diffraction, 4D-STEM and in situ TEM mechanical testing to provide insight into the structure and role of short range order (SRO) in materials. Examples will be presented from structural alloys such as Ti-6Al [1], high entropy alloys [2-5], and semiconductors such as a SiGeSn[6]. We will show how coordinated computational methods to simulate diffraction patterns for direct comparison with experimental measurements can help to interpret the ambiguous diffuse intensities in both dilute alloys and concentrated solid solutions. Lastly, we will discuss both the strengths and limitations of electron microscopy methods for analyzing SRO in these systems.
References:
[1] Ruopeng Zhang, Shiteng Zhao, Colin Ophus, Yu Deng, Shraddha J. Vachhani, Burak Ozdol, Rachel Traylor, Karen Bustillo, J.W. Morris, Jr., Daryl C. Chrzan, Mark Asta, Andrew M. Minor, "Direct imaging of short-range order and its relationship to deformation in Ti-6Al", Science Advances, 5, no. 12 (2019)
[2] Ruopeng Zhang, Shiteng Zhao, Jun Ding, Yan Chong, Tao Jia, Colin Ophus, Mark Asta, Robert O. Ritchie & Andrew M. Minor "Short-Range Order and Its Impact on the Properties of the CrCoNi Medium Entropy Alloy" Nature, 581, 283-287 (2020)
[3] Mingwei Zhang, Qin Yu, Carolina Frey, Flynn Walsh, Madelyn I. Payne, Punit Kumar, Dongye Liu, Tresa M. Pollock, Mark D. Asta, Robert O. Ritchie, and Andrew M. Minor, "Determination of peak ordering in the CrCoNi medium-entropy alloy via nanoindentation", Acta Materialia, 241, 118380 (2022)
[4] Y. Yang, S. Yin, Q. Yu, Y. Zhu, J. Ding, R. Zhang, C. Ophus, M. Asta, R.O. Ritchie, A. M. Minor, "Rejuvination as the origin of planar defects in the CrCoNi medium entropy alloy", Nature Communications, 15, 1402 (2024)
[5] Flynn Walsh, Mingwei Zhang, Robert O. Ritchie, Mark Asta, Andrew M. Minor, "Multiple origins of extra electron diffractions in fcc metals", Science Advances, 10, no. 31 (2024)
[6] Lilian M. Vogl, Shunda Chen, Peter Schweizer, Xiaochen Jin, Shui-Qing Yu, Jifeng Liu, Tianshu Li, Andrew M Minor "Identification of short-range ordering motifs in semiconductors", Science 389, 1342-1346 (2025)
More about the Speaker:
Andrew M. Minor is the Chancellor's Professor in the Department of Materials Science and Engineering at the University of California, Berkeley. He also holds a joint appointment at the Lawrence Berkeley National Laboratory where he is the Facility Director of the National Center for Electron Microscopy in the Molecular Foundry. He has over 300 publications in the fields of nanomechanics, metallurgy, electron characterization of soft matter and in situ transmission electron microscopy technique development. Minor's honors include the Hardy Award from TMS (2012), and the Burton Medal from MSA (2015). In 2023, he served as President of the Microscopy Society of America.