About

Professor Udo D. Schwarz is associated with the Yale Nanoprobe Group, where his research focuses on visualizing and probing the nanoworld through the exploration and quantification of nanometer-scale mechanical, physical, and chemical properties of surfaces and interfaces. His group specializes in using local probe-based techniques, particularly advanced atomic force microscopy and related scanning probe methods, which are continuously developed in his lab. These techniques are employed to measure and map surface forces, interaction energies, mechanical properties such as hardness and Young's modulus, as well as parameters like tunneling currents and charge distributions with high resolution. His work aims to understand the atomistic origins of material interactions by conducting site-specific measurements, ultimately enabling the tailoring of surface properties within certain limits. Results from these measurements are complemented with data obtained through various microscopy, spectroscopy, mechanical, and thermal testing approaches. His current projects address problems in materials science, surface physics, catalysis, and nanomechanics.

Research topics

• Composite material
• Materials science
• Thermodynamics
• Physics
• Mechanics
• Chemical physics
• Chemistry
• Metallurgy
• Nanotechnology

Selected publications

• Effect of fictive temperature on tribological properties of Zr44Ti11Cu10Ni10Be25 bulk metallic glasses

  Wear · 2021 · 21 citations

  • Materials science
  • Composite material
  • Metallurgy
  DOI

• Atomic-scale homogeneous plastic flow beyond near-theoretical yield stress in a metallic glass

  Communications Materials · 2021 · 20 citations

  Senior authorCorresponding
  • Materials science
  • Composite material
  • Mechanics

  Abstract The onset of yielding and the related atomic-scale plastic flow behavior of bulk metallic glasses at room temperature have not been fully understood due to the difficulty in performing the atomic-scale plastic deformation experiments needed to gain direct insight into the underlying fundamental deformation mechanisms. Here we overcome these limitations by combining a unique sample preparation method with atomic force microscopy-based indentation, which allows study of the yield stress, onset of yielding, and atomic-scale plastic flow of a platinum-based bulk metallic glass in volumes containing as little as approximately 1000 atoms. Yield stresses markedly higher than in conventional nanoindentation testing were observed, surpassing predictions from current models that relate yield stress to tested volumes; subsequent flow was then established to be homogeneous without exhibiting collective shear localization or loading rate dependence. Overall, variations in glass properties due to fluctuations of free volume are found to be much smaller than previously suggested.

  DOI

• Atomic imprinting in the absence of an intrinsic length scale

  APL Materials · 2020 · 15 citations

  Senior authorCorresponding
  • Materials science
  • Nanotechnology
  • Chemical physics

  Bulk metallic glasses (BMGs) have successfully been used to replicate molds that are structured at the nano- and even atomic scale through thermoplastic forming (TPF), an ability that was speculated to be rooted in the glass’ featureless atomic structure. These previous demonstrations of atomically precise imprinting, however, were performed under conditions where mold atomic feature dimensions coincided with the unit cell size of constituents in the BMG. In order to evaluate if accurate atomic-scale replication is possible in general, i.e., independent of the accidental presence of favorable constituent size/feature size relationships, we have used Pt57.5Cu14.7Ni5.3P22.5 to replicate three different crystalline facets of LaAlO3 single crystals, each exposing distinct atomic step heights. We find that in all cases, the terraced surface termination can be copied with remarkable fidelity, corroborating that BMGs when thermoplastic formed are capable of adapting to any externally imposed confinement with sub-angstrom precision without being limited by factors related to the specifics of their internal structure. This unprecedented capability of quasi-limitless replication fidelity reveals that the deformation mechanism in the supercooled liquid state of BMGs is essentially homogeneous and suggests TPF of BMGs to be a versatile toolbox for atomic and precision nanoscale imprinting.

  DOI

Recent grants

• Chemical Imaging of Elementary Steps in Hydrogenation Reactions of Surfaces

  NSF · $150k · 2016–2018

• Unraveling the Fundamental Mechanisms of Nanoscale Deformation in Bulk Metallic Glasses

  NSF · $729k · 2019–2022

• CAS-Climate: Atomically Resolved Single-Molecule Microscopy of Catalytic Intermediates in CO2 Reduction

  NSF · $474k · 2022–2026

• Chemical Imaging of Elementary Steps in Hydrogenation Reactions of Surfaces

  NSF · $490k · 2018–2022

• Materials World Network: Mapping Oxide Surface Reactivity Through Spacially-Resolved Atomic Interaction Forces

  NSF · $420k · 2008–2012

Frequent coauthors

• Eric I. Altman

  Yale University

  131 shared

• Omur E. Dagdeviren

  Université du Québec à Montréal

  77 shared

• Hendrik Hölscher

  Karlsruhe Institute of Technology

  71 shared

• André Schirmeisen

  65 shared

• Mehmet Z. Baykara

  56 shared

• Chao Zhou

  Jilin University

  50 shared

• Jürgen Kurths

  Potsdam Institute for Climate Impact Research

  47 shared

• Todd C. Schwendemann

  Southern Connecticut State University

  46 shared

Education

• Habilitation, Applied Physics

  Universität Hamburg

  1999

• Ph.D., Physics

  University of Basel

  1993

• Diploma, Physics

  University of Basel

  1989

Awards & honors

• Magister of Arts Privatim (honorary degree, Yale University,…
• Heisenberg Fellowship (German Research Society, 2000)
• Gaede Award (Principal Prize of the German Vacuum Society, 1…
• German "Habilitation" (University of Hamburg, Germany, 1999)
• Venia Legendi ("Privatdozent") (University of Hamburg, Germa…

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• Alan Kazdinh-142
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