Strong interactions at the interface between a crystalline film and substrate can impart new structure to thin films. Here, a germanium surface (purple atoms) squeezes a BaTiO3 thin film above, revealing a hidden phase not seen in the bulk. The hidden phase of BaTiO3 shows oxygen octahedra cages (shaded in aqua) alternating in size.
There is an abiding interest in using nanocrystals as laser gain media due to their tunable emission wavelengths, low cost, and solution processability. However, it has been proven difficult to achieve low lasing thresholds suitable for practical applicatons.
We introduced the concept of plate mechanical metamaterials [1] and its initial realization in the form of freestanding corrugated plates made out of ultrathin films.
The NSF has awarded additional funds to support helium conservation in the Property Measurement Shared Experimental Facility (SEF). The SEF hosts over a dozen low temperature measurement capabilities requiring liquid helium.
Optimum function of plasmonic nanocrystal in assembly requires precision control of separation. Often, larger separations are desired while still maintaining order. With our COMPASS collaborators, Hough and Donnio, IRG-4 has developed a new class of building blocks that incorporate dendrimer ligands.
A metal spoon can bend in half without breaking because of defects in its crystalline structure. By contrast, a metal spoon with atoms in a disordered structure—a metallic glass spoon—would break via a catastrophic brittle fracture. Here we show that disordered packings of particles ranging in size from atoms, as in a metallic glass, to nanoparticles to micron-sized colloids to centimeter-siz
To increase our online presence, we are recording nearly all outreach presentations and making them available on our website (www.lrsm.upenn.edu/outreach/videos). These include Science Cafes, PREM seminars (given usually in Spanish), and various other events.
