Special Seminar on Materials Science and Engineering
IAMM 147, 11am-12:15pm, August 23, 2022
Nanoimprinting atomically smooth surfaces for nanoscale measurements of bulk metallic glasses
Dr. Amit Datye, Yale University Hosted by Prof. Yanfei Gao at MSE (ygao7@utk.edu)
In recent years, nanoimprinting of bulk metallic glasses (BMGs) by thermoplastic forming has enabled the manufacturing of samples made from Pt57.5Cu14.7Ni5.3P22.5 BMG featuring atomically smooth terraces using SrTiO3 single crystals as molds. Due to their sub-angstrom RMS surface roughness, these atomically smooth samples are ideally suited to be used in high-resolution investigations of BMG properties by surface-sensitive methods such as atomic force microscopy.
We will discuss three additional aspects of BMG-based replication: First, we establish that there is indeed no intrinsic length scale that would limit the accuracy of replication of angstrom-scale surface features; second, we demonstrate a new route to manufacturing highly accurate crystalline copies of surfaces by heating BMGs in-situ while being pressed into form for sufficiently long times that almost complete crystallization has been achieved; and third, we introduce an alternative replication methodology based on sputtering amorphous thin films that has the potential to be economic for large-scale industrial application even on soft and temperature-sensitive molds while still providing sub-angstrom replication accuracy
Finally, in this talk, results of nanoscale measurements for studying the effect of annealing-induced relaxation and crystallization on surface morphology and mechanical measurements of atomic flow in glasses is also presented.
Dr. Amit Datye is currently an Associate Research Scientist in the Department of Mechanical Engineering and Materials Science at Yale University. He received his PhD under the guidance of Prof. George Pharr at the University of Tennessee, Knoxville. While working on this PhD, he conducted research at the Oak Ridge National Laboratory. He joined Yale University after a brief one year at Cornell University. He is an author or co-author of more than 50 scientific publications (including 4 book chapters) in prestigious journals like Nature Communications, Nature Communications Materials, Nature Communications Physics etc. His research focuses on nanoscale characterization techniques and advanced manufacturing techniques like imprinting and additive manufacturing.