Single-crystal organic field-effect transistors (OFETs) are ideal device structures for studying fundamental science associated with charge transport in organic materials and have demonstrated outstanding electrical characteristics. However, it remains a technical challenge to integrate single-crystal devices into practical electronic applications. A key difficulty is that organic single-crystal devices are usually fabricated one device at a time through manual selection and placing individual crystals. To overcome this difficulty, Bao et al.

Producing high quality thin films of controlled thickness is a critical step for the development of ferroelectric nanophotonic devices. Developed recently, the process referred to as layer transfer has been shown to be very promising: ions are implanted in a plan parallel to the interface of a bilayer system that is then heated. The high temperature induces nucleation and propagation of cracks in the weakened plan of the specimen, resulting after coalescence in a full splitting of the upper part of the original sample (Fig. (a)).

In a recent publication in Nature, we reported bulk metallic glass (BMG) matrix composites exhibiting >10% tensile ductility and Fracture Toughness comparable to or exceeding the toughest metals known [1]. These high performance composites demonstrate the potential of metallic glass as revolutionary structural metals. The BMG matrix composites contain elastically soft dendrites comprised of Ti-Zr-Nb embedded in a glassy matrix. Toughening and ductility are achieved by a mechanism similar to the

In a normal material, electrons repel each other due to their charge. In the copper-oxide superconductors, however, an attractive force develops between electrons that pairs them up at temperatures up to 140 degrees above absolute zero. Understanding the reason for this pairing has remained an elusive goal in condensed matter physics research over the past two decades.

The energy E of a bowling ball increases as the square of its velocity (or momentum p). This is also generally true for electrons in solids, which are accurately described by the Schràƒ’¶dinger equation (Fig. 1a). However, in a small set of materials - e.g. bismuth, antimony and graphene - E increases linearly with p (Fig. 1b). To describe this unusual behavior, we resort to the Dirac equation, which has been very successful in describing neutrinos and high-energy electrons.

Organic photovoltaic devices (OPVs) hold promise for a variety of applications requiring alternative energy generation. Through a collaboration betweenÂ’  Northwestern University MRSEC IRG 4 and Wright Patterson Air Force Base, a new strategy for characterizing the electrical and optical performance of operating OPVs has recently been developed. Atomic force photovoltaic microscopy allows the photocurrent response in OPVs and other optoelectronically-active materials and devices to be spatially mapped down to the nanometer length scale.

Self-assembling block copolymers provide a simple, efficient, and rapid way to generate nanoscale patterns over macroscopic areas:Â’  for example, an array of 20 nm dots covering a 100 mm silicon wafer.Â’  These dots can be "lined up" by applying shear to the block copolymer film [1], but the order is not perfect:Â’  dislocations (lines of dots that abruptly start or end) remain in the film.Â’  In a recent study [2], PCCM researchers have shown that the quality of orientational order of the dots depends only on the density of these dislocations; in the limit that dislocations are

MRSEC faculty members Paul Crowell, Chris Leighton, and Dan Dahlberg and their students guided 25 high school students through an exploration of magnetism and its applications to technology as part of the Institute of Technology Center for Education Programs (ITCEP) Exploring Careers in Science & Engineering summer camp. The day of activities included hands-on demos, a lunch with recent graduates working in industry, and an afternoon spent building motors, magnetic levitators, generators, and radios.

The UMN MRSEC has demonstrated the control of nanocrystal orientation within nanoporous polymer monoliths prepared from ABC triblock terpolymers containing a robust A block (polystyrene), a hydrophilic B block [poly(dimethylacrylamide)], and an etchable C block (polylactide) developed in the IRG.