Lagally, Larbalestier Lead Interdisciplinary Research Groups in New NSF-Funded Research Center

The Materials Science & Engineering Department is one of five UW-Madison departments participating in the development of a Materials Research Science and Engineering Center (MRSEC) on the UW-Madison campus. Funded by a $10.6 million grant from the National Science Foundation (NSF), the Center is dedicated to understanding nanostructured materials and interfaces. Since September 1996, twenty-four senior researchers from the UW-Madison have been working closely with each other and with collaborators from industry and national laboratories to conduct a wide range of superconductor and nanostructured materials research.

Directed by Professor Thomas F. Kuech from the Department of Chemical and Biological Engineering, the Center brings together two existing NSF Materials Research Groups and initiates two new exploratory groups. The two existing groups are both headed by MS&E faculty. MS&E Professor Max G. Lagally leads a research group investigating the fundamental mechanisms of semiconductor film growth and Professor David C. Larbalestier leads a group that researches current transport across interfaces in high-temperature superconductors.

Funded by a $10.6 million grant from the National Science Foundation (NSF), the Center is dedicated to understanding nanostructured materials and interfaces.

The semiconductor film growth research group includes five faculty members from four departments: Gentry E. Crook and Leon McCaughan (Electrical and Computer Engineering), Don Gaines (Chemistry), Thomas F. Kuech (Chemical and Biological Engineering) and Max G. Lagally (MS&E). The aim of this research is to investigate the fundamental mechanisms of growth in chemical vapor deposition, the most commonly used but least understood of the several methods for depositing single-crystal films of semiconductors. The group is interested in developing in-situ diagnostics of the growth, in obtaining an atomistic understanding of the growth process, and in using this knowledge to develop novel nanoscale structures and devices. As part of this work, the group is investigating the growth of "quantum dot" structures. Quantum dot structures are very small three-dimensional crystallites whose formation is controlled by strain when two lattice-mismatched materials are deposited on each other. These structures may be the building blocks of future generations of computers or of novel optoelectronic devices. This group, working in prior years as a Materials Research Group, has already developed several new diagnostic techniques for characterizing film growth.

Larbalestier's group, working closely with groups led by Susan E. Babcock (MS&E), Bob Joynt (Physics), Marshall F. Onellion (Physics), and Mark Rzchowski (Physics) are taking an interdisciplinary attack to solving the complexities of current transport across interfaces in high-temperature superconductors. Their current research emphasizes the electromagnetic and microstructural study of the percolation of supercurrent through polycrystalline superconductors and the study of the superconducting energy gap symmetry by photo-emission.

"Grain boundaries are one of the principal barriers to current flow in high-temperature superconducting (HTS) wires," noted Larbalestier. "They control the supercurrent flow on the scale of nanometers and stand in the way of making a viable technology from HTS wires. With more than seven years of working together as a NSF Materials Research Group, the MRSEC's predecessor, we are in a unique position to break new ground--to unite physics and materials science, theory and experimentation to solve this immensely complex problem and pave the way for new technology," he concluded.

The funding of the Materials Research Science and Engineering Center by the NSF helps keep UW-Madison at the forefront of critical research. Nanostructured materials and superconductor research are widely accepted by both government and industry as being at the heart of new technological developments.