Au Nanopillar Array Prepared by Selective Etching of Au-Sr3Al2O6 Vertically Aligned Nanocomposite Thin Films

6/24/2024 | Haiyan Wang (Purdue University)

These findings provide a novel strategy for tailoring the Au nanostructures and their optical properties while demonstrating on-chip integration for advanced optical device applications.

Melting temperature of silicate T/EBCs

6/5/2024 | Elizabeth Opila, University of Virginia

Rare-earth silicates are the current standard material for use as environmental barrier coatings for SiC-based ceramic matrix composites as hot-section components in gas-turbine engines. Expanding the design space to all available rare-earth elements to facilitate optimizing functionality requires an understanding of systematic trends in RE2Si2O7 properties. In this work, we combine first-principles calculations with experimental measurements of Young’s modulus, coefficient of thermal expansion, and thermal conductivity for a range of different RE2Si2O7 compositions and phases.

Transient Phase Formation within Rare-Earth Disilicates

6/5/2024 | Elizabeth Opila, University of Virginia

A transient triclinic crystal phase is identified during the crystallization of multi-component rare-earth disilicates. This transient phase has a density that is approximately 10% higher than that of the final monoclinic phase. This is critically significant in use of these materials in coating applications as the initial crystallization will result in large thermal stresses owing to this phase transformation.

Octopus-inspired Adhesive Skins for Intelligent and Rapidly Switchable Underwater Adhesion

5/30/2024 | Michael Bartlett (Virginia Tech.)

The octopus couples controllable adhesives with intricately embedded sensing, processing, and control to manipulate underwater objects. Current synthetic adhesive–based manipulators are typically manually operated without sensing or control and can be slow to activate and release adhesion, which limits system-level manipulation. Here, we couple switchable, octopus-inspired adhesives with embedded sensing, processing, and control for robust underwater manipulation.

Deep Learning Accelerated Design of Mechanically Efficient Architected Materials

5/30/2024 | Grace Gu (U. CA – Berkeley)

Lattice structures are known to have high performance-to-weight ratios because of their highly efficient material distribution in a given volume. However, their inherently large void fraction leads to low mechanical properties compared to the base material, high anisotropy, and brittleness. Most works to date have focused on modifying the spatial arrangement of beam elements to overcome these limitations, but only simple beam geometries are adopted due to the infinitely large design space associated with probing and varying beam shapes. Herein, we present an approach to enhance the elastic modulus, strength, and toughness of lattice structures with minimal tradeoffs by optimizing the shape of beam elements for a suite of lattice structures.

Data-mining our Way to Better Nanoparticle Structures

5/28/2024 | Simon Billinge (Columbia University)

Crystallography has given us the positions of atoms in crystals for 100 years, but nano-particles require a radical rethink in approach. They form interesting non-space-filling structures that we want to synthesize and control for advanced devices, but how to accurately determine the 3D atomic arrangements?

Teaching a Machine to See Symmetry Where We Can’t

5/28/2024 | Daniel Hsu, Qiang Du, Simon Billinge (Columbia University)

Atoms typically arrange themselves in symmetric arrangements making patterns. The first step in any structure solution is determining these symmetries from the diffraction data. But in typical nanoparticle data the underlying symmetries are hidden.

Control of Electronic Properties of MXenes

5/28/2024 | Simon Billinge (Columbia University)

Over the past decade, graphene and other two-dimensional (2D) materials opened new horizons for research, from miniaturizing electronic devices to creating wearable electronics and developing new methods for water desalination and purification. 2D transition metal carbides (MXenes) are among the latest additions.

The Mathematics of Finding Atoms in Nanoparticles

5/28/2024 | Simon Billinge (Columbia University)

When atoms arrange themselves in crystals, x-ray crystallography can be used to find them. In nanostructures, atoms are much harder to find.

A New View of Grain Boundary Migration in Polycrystals

5/22/2024 | G. Rohrer, K. Dayal (Carnegie Mellon University) A. Krause (University of Florida)

Grain boundary migration during annealing is an important process because of the role it plays in determining the microstructure and properties of polycrystalline metals and ceramics. We have used high energy x-ray diffraction microscopy to image the microstructure of α-Fe, an ideal model for commercially important steels, before and after a 600 °C anneal.

Research Highlights