Dr. Laura H. Lewis

Cabot Professor

B.A. (Physics with Specialization in Earth Sciences)
University of California, San Diego, 1985

M.S. (Electronic Materials)
Massachusetts Institute of Technology, 1988

Ph.D. (Materials Science and Engineering)
University of Texas at Austin, 1993




Contact
Phone: 617.373.3419
Email: lhlewis@neu.edu
Website: Nanomagnetism

Research Focus/Background

Magnetic materials are ubiquitous in society, providing functionality to advanced devices, sensors and motors of every kind. As the magnetic force maintains strength over large distances, it allows for communication between components that are physically separated. This unique property permits the conversion of electrical to mechanical energy, assists microwave devices in telecommunications, transmits and distributes electric power and provides the basis for data storage systems. Magnetic materials are increasingly employed in medical applications, not only in NMR diagnostic equipment but also in specialized targeted cancer treatments and drug delivery protocols. It is anticipated that specialized engineering of magnetic materials and careful tailoring of their properties will enable a new generation of stronger and more responsive materials and devices that can significantly impact the way we use and store energy.

Current research is devoted to understanding magnetostructural transitions, which comprise simultaneous magnetic and structural phase changes. These transitions are attracting new attention due to the recognition that they underlie an assortment of “extreme” phenomena with important technological implications, such as Colossal Magnetoresistance (CMR) of interest for magnetic sensors in the recording industry; the giant Magnetocaloric Effect (MCE) under intense development for CFC-free magnetic refrigeration, and exceptional magnetomechanical behavior for actuators. Magnetostructural transitions may be driven by multitude of physical inputs (magnetic field, temperature, pressure, electric field), implying they may be manipulated to yield a tailored functional response. Our research employs advanced materials probes and techniques (magnetic measurement, advanced electron microscopy and specialized synchrotron scattering and spectroscopic techniques) that are available both at Northeastern University and at the Brookhaven National Laboratory in Long Island, New York.

Other research: Rare earth elements and global energy strategy

Research Areas:

• Magnetostructural phase transitions in bulk and nanoscaled systems
• Exchange coupling in magnetic nanocomposites
• Manipulation of interphase interfaces in magnetic systems
• Novel synthesis routes to magnetic systems
• Magnetism and atomic defects

Publications:

“Advances in Nanomagnetism via X-ray Techniques”, G. Srajer, L. H. Lewis, S. D. Bader, C. S. Fadley, E. E. Fullerton, A. Hoffmann, J. B. Kortright, Kannan M. Krishnan, S. A. Majetich, T. S. Rahman,C. A. Ross, M. B. Salamon, I. K. Schuller, T. C. Schulthess and J. Z. Sun; review article, Journal of Magnetism and Magnetic Materials, 307 (1) 1-31 (2006).

“Magnetic Aspects of the Ferromagnetic “Bulk Metallic Glass” Alloy System Nd-Fe-Al”, R.W. McCallum, L. H. Lewis, M. J. Kramer and K. W. Dennis, Journal of Magnetism and Magnetic Materials 299 (2) 265 – 280 (2006).

“Magneto-structural transition and magnetocaloric effect in Ni55Mn20Ga25 single crystals”, M. Pasquale, C. P. Sasso, L. H. Lewis, L. Giudici, T. Lograsso, D. Schlagel, Physical Review B72 94435 (2005).

“Alignment and analyses of MnBi/Bi nanostructures”, K. Kang,, L. H. Lewis, and A. R. Moodenbaugh, Applied Physics Letters 87 062505 (2005).

“Interphase Exchange Effects in CoPt/Co Bilayer Thin Films”; L. H. Lewis, J. Kim, K. Barmak, and D. C. Crew, Journal of Physics D: Applied Physics 37 (19) 2638-2642 (2004) 2638-2642.