A group led by Sandia staff member Jianyu Huang (left) recently reported in the journal Science the creation of the world’s smallest battery inside a transmission electron microscope. In this work, researchers directly observed chemistry working to change the battery’s microstructure at atomistic length scales, which provided new insight into the electrochemical processes critical to developing new high-performance batteries. (1100) ECIS

Graphene is a promising advanced electronics device material. The development of large-area high-mobility graphene on suitable substrates is a key challenge. Taisuke Ohta (1114) and Norm Bartelt (8656) used coordinated low energy electron microscopy measurements and computational modeling to further the scientific understanding of graphene on silicon carbide growth. Their understanding of the role of atomic steps on silicon carbide led to an engineered step-flow growth route for producing large-area graphene films with improved domain size and mobility characteristics. (1100, 8600) DS&A

Metallic friction is an important engineering concern for Sandia applications. Nanocrystalline nickel and some crystallographic orientations of single-crystal nickel exhibit unusually low sliding friction (approximately 0.3 microns) at low contact stresses and sliding velocities. Researchers have employed nanopillar compression experiments on the thin layer of wear material formed underneath the sliding contact and discovered that this tribologically induced layer is notably softer than the parent material. This surprising result helps explain the mysterious frictional behavior and is hypothesized to be related to a dislocation “de-starvation” process. (1800) ECIS

Researchers in the Energetics Characterization Department used ion-beam nano-tomography to cross-section explosive pellets, giving the first-ever high-resolution images of the internal microstructure of explosives. Resulting data has provided high fidelity three-dimensional representations of explosive microstructure, which can be directly used in hydrocode simulations. This work is a key component of a larger effort to build a science-based understanding of explosives initiation necessary for the design and evaluation of new devices. (2500, 1500) NW

Each citation is followed by the center numbers of centers that contributed most directly to the effort described. An acronym after each accomplishment indicates which of Sandia’s strategic management units (SMUs) or strategic management groups (SMGs) the work most directly supported.

The SMG/SMU acronyms are:

• NW: Nuclear Weapons SMG & SMU
• DS & A: Defense Systems & Assessments SMU
• IHNS: International, Homeland, and Nuclear Security SMU
• ECIS: Energy, Climate, and Infrastructure SMU
• IES: Integrated Enabling Services SMU
• SPP: Sandia Partnership Projects