Condensed Matter and Materials

Experimental work in progress includes a wide variety of projects in solid state physics, chemical physics, high pressure physics, and materials physics.

Magnetic Resonance

In magnetic resonance, spins precess about a magnetic field, H, at a frequency proportional to H. The magnetic field arises from nearby electron and nuclear spins and electronic currents, as well as the externally applied field. The resonance can be used to study the structure and atomic motions of solids and liquids, addressing a remarkably wide range of questions. The efforts of Professor Conradi in NMR are strengthened by collaborations with resonance groups in the Department of Chemistry in Arts & Sciences.

Superconductivity and Magnetism

In the Laboratory for High-Pressure Physics, Professor Schilling's group is studying the superconducting and magnetic properties of matter under variation of the lattice parameters, thus allowing a comparison with predictions from theory. In addition, the application of high pressures and/or high temperatures can induce new states of matter with novel properties. Topics currently under investigation include high-temperature superconductivity in both oxide and buckminsterfullerene C₆₀ compounds and the anomalous magnetic state of heavy-fermion systems.

Ultrasonic Physics of Composite Materials

One area of active research within the Laboratory for Ultrasonics is the development of ultrasonic techniques that provide a quantitative approach to the investigation of the physical properties of advanced composite materials, such as fiber-reinforced polymer-based resins and metal matrix materials. The physical principles underlying the interaction of ultrasonic fields with anisotropic elastic properties of composites are being studied by Professor Miller's group through broadband measurements of ultrasonic velocity, attenuation, and backscatter.

Materials Physics

Professor Kelton's group is working to better understand the physical principles governing phase formation and stability and microstructural development. Professor Kelton's studies are focused on the nucleation and growth of condensed phases, the formation of metallic glasses and their crystallization to consolidated nanostructured materials, the structure and formation of quasicrystals and their hydrogen storage properties.

Professor Gibbons' research group uses the transmission electron microscope with its electron-energy-loss and energy-dispersive X-ray spectrometers to investigate a wide variety of materials. Working with Professor Kelton's group, Professor Gibbons has several projects in the study of quasicrystals. The electron microscope allows study of single quasicrystal samples, whcih are typically 50-500 nm in diameter. Professor Gibbons and his students study electronic and lattice structure of quasicrystals and related, metastable crystal phases using energy-loss spectroscopy and electron diffraction.

Professor Solin's group conducts research on:

1. The fundamental phenomena that underpin the new class of macroscopic and nanoscopic "EXX" sensors where E = extraordinary and XX = magnetoresistance (MR), optoconductance (OC), etc.
2. Understanding the mesoscopic physics of EXX nano arrays that are targeted for the real-time imaging of properties of cancer cells.
3. Magnetic frustration and 2D phase transitions in novel materials such as copper-hydroxy-nitrate that model a spin 1/2 triangular lattice Heisenberg antiferromagnet.
4. The interplay between structural and electrical properties of pentacene organic thin film transistors.