The Gu Group works at the intersection of solid mechanics, materials science and nano-chemistry. We study the mechanical behavior of nanoscale metals and hybrid materials, the effect of strain and crystalline defects on optical nanomaterials, and the self-assembly and 3D printing of nano-architected composites.
Ductile Metallic Glass Nanoparticles via Colloidal Synthesis
Published in Nano Letters in August 2020!
The design of ductile metallic glasses has been a longstanding challenge. Here, we use colloidal synthesis to fabricate nickel–boron metallic glass nanoparticles that exhibit homogeneous deformation at room temperature and moderate strain rates. In situ compression testing is used to characterize the mechanical behavior of 90–260 nm diameter nanoparticles. The force–displacement curves consist of two regimes separated by a slowly propagating shear band in small, 90 nm particles. The propensity for shear banding decreases with increasing particle size, such that large particles are more likely to deform homogeneously through gradual shape change. We relate this behavior to differences in composition and atomic bonding between particles of different size using mass spectroscopy and XPS. We propose that the ductility of the nanoparticles is related to their internal structure, which consists of atomic clusters made of a metalloid core and a metallic shell that are connected to neighboring clusters by metal–metal bonds.
We are currently looking for highly motivated students and postdocs who enjoy working in a collaborative setting to join our team. We welcome researchers with backgrounds in Mechanical Engineering, Materials Science, Chemical Engineering, Chemistry, Physics and related fields.
Students who have already been accepted to Stanford University can contact us with a CV , and a request to set up a meeting to discuss research interests. Postdocs are encouraged to contact us with a CV, and a statement of research and career goals.