Maxim Shugaev, a post-doc in the Department of Materials Science and Engineering at the University of Virginia, has earned the Dieter W. Baeuerle Prize for Fundamentals and Applications of Laser-Matter-Interaction.The Dieter W. Baeuerle Foundation awards the prize to young scientists whose research concerns the fundamentals and applications of laser-matter interaction in physics, chemistry, life science, medicine and art, and who completed their doctoral dissertation or Ph.D. study within 10 years of their nomination. The award ceremony will be held at Johannes Kepler University Linz, Austria, as soon as the COVID situation allows.
Shugaev earned his degree in engineering physics in 2019, advised by Leonid Zhigilei, professor of materials science and engineering, and joined Zhigilei's computational materials research group as a post-doc after graduation.
“It's quite important to have an agreement between theory and experimental work,” Shugaev said. Describing material behavior during thermodynamic flux—as a material changes from one form to another—is challenging and often requires scientists and engineers to revise or develop new theoretical models and computational approaches.
“The intricate connections between ultrafast material response to laser excitation, generation of crystal defects, phase transformations and mass transfer that occurs under highly nonequilibrium conditions can only be explained by combining the research expertise and theoretical approaches from different disciplines,” Shugaev said.
Shugaev has observed very good agreement between his computational predictions and experimental studies performed through collaborative research. His development of a non-thermal approach to thin-film deposition is one exemplar.
Usually, thin film deposition requires high levels of energy to achieve the individual chemical steps to deposit a coating on a substrate. Conventional means initiate this chemical process by applying very high temperatures, more than 1000 degrees Kelvin, which often exceed the maximum temperatures that the substrate material can withstand.
Shugaev's alternative method relies on acoustic activation through laser irradiation to produce very strong bulk and surface acoustic waves to transfer energy directly to the surface species. Shugaev's simulation predicted a dramatic—more than 4500-fold—increase of surface mobility. Results of this study are documented in Strong Enhancement of Surface Diffusion by Nonlinear Surface Acoustic Waves, published in Physical Review B.
If borne out in practice, this enhancement may create the equivalent of a 1000 degree Kelvin surface diffusion at room temperature. Such a breakthrough could enhance performance and enable new capabilities across a range of technologies including coatings for wear resistance, corrosion resistance, high temperature protection and erosion protection, and innovate the design of integrated circuits, sensors, photovoltaics and optoelectronic devices.
More recently, Shugaev first-authored Molecular Dynamics Modeling of Nonlinear Propagation of Surface Acoustic Waves, published July 2020 in the Journal of Applied Physics. Shugaev and his co-authors detail how to simulate surface acoustic waves with molecular dynamics, demonstrate main effects and compare results with known analytical dependencies. This paper, promoted as an editor's pick for Scilights, presents the first framework for atomistic simulation of free propagation of surface waves.
As a graduate student, Shugaev benefited from his collaboration with fellow computational materials research group member Cheng-Yu Shih, who earned his Ph.D. in materials science and engineering in 2017. Together they explored material behavior and nanoparticle generation under pulsed laser ablation in liquids.
“This method is nice because the produced nanoparticles are contamination free and can be used for health applications,” Shugaev said.
The issue is that laser irradiation typically produces particles that differ in size: large particles that are 10s and 100s of nanometers and small particles that are just 1 to 10 nanometers. Shih and Shugaev's simulations provide insights into the mechanisms of nanoparticle formation in laser ablation in water and reveal the origins of the bimodal nanoparticle size distribution.
“We believe our simulation will help generate nanoparticles of a more uniform size and ease the nanoparticles' use in applications without additional post-processing,” Shugaev said. For this work, Shih's project team earned the decennial award for best innovative research article related to advanced nanoparticle generation and excitation by lasers in liquids (ANGEL) in the years 2010-2020.
Shugaev's research also answered the question on the mechanism of single pulse formation of laser-induced periodic surface structures. These structures are represented by parallel hills and troughs only a hundred nanometers deep. Despite the small size of the features, physical properties of the surfaces are altered in ways that allow for the control of processes such as light absorption, wettability and adhesion, as well as the growth and migration of cells. Shugaev's first-authored paper, Mechanism of Single-pulse Ablative Generation of Laser-induced Periodic Surface Structures, published in Physical Reviews B, presents the results of experiments, analysis and theory underlying the model.
Another area of research where Shugaev has obtained very interesting results is the generation of crystal defects in laser-irradiated targets. Shugaev explained the appearance of sub-surface twinned domains and the dependence of the generation of dislocations on crystallographic orientation of targets irradiated by femtosecond laser pulses, observed in experiments performed by collaborators at the Université Jean Monnet, Saint Étienne, France. The results on the subsurface twinning have been reported in Growth Twinning and Generation of High-Frequency Surface Nanostructures in Ultrafast Laser-Induced Transient Melting and Resolidification, published in ACS Nano, a journal of the American Chemical Society.
Shugaev's recognition by the world-wide research community is reflected by an invitation he received to lead a team of researchers from the United States, Germany, Austria and the Czech Republic in writing a review on the fundamentals of ultrafast laser-material interaction for MRS Bulletin. Published in December 2016, this review appeared on the cover and has earned more than 80 citations.
“The Baeuerle Prize recognizes the broad range of Maxim's research interests, his high productivity and creativity,” Zhigilei said.
Shugaev will join Intelligent Automation, a technology innovation company that develops cutting-edge technology and solutions for future battlefields based in Rockville, Maryland, as a research scientist in computer vision and machine learning.
“I truly believe that everything that we are doing is related, and one never knows how the things we learned in the past could help us in the future,” Shugaev said. “The really important thing is to acquire key concepts and relate them to knowledge you already have. Harnessing a method you already know to a new concept could generate the next novel idea or method.”