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. 

Articles

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Toward tailored functionality of titania nanotube arrays: Interpretation of the magnetic-structural correlations (with Pegah M. Hosseinpour, Eugen Panaitescu, Don Heiman, and Latika Menon), Physics Faculty Publications (2013)

Ordered arrays of titania nanotubes (NTs) are considered as good candidates for photocatalytic applications including...

 

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Tuning the magnetostructural phase transition in FeRh nanocomposites (with Radhika Barua, Xiujuan Jiang, Felix Jiménez-Villacorta, J. E. Shield, and D. Heiman), Chemical Engineering Faculty Publications (2013)

Effects of nanostructuring on the magnetostructural response of the near-equiatomic FeRh phase were investigated in...

 

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Tailoring the FeRh magnetostructural response with Au diffusion (with M. Loving, M. A. de Vries, F. Jimenez-Villacorta, C. Le Graët, X. Liu, R. Fan, S. Langridge, D. Heiman, and C. H. Marrows), Chemical Engineering Faculty Publications (2012)

Factors which contribute to magnetostructural transition control have been demonstrated by study of the effects...

 

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Magnetic signature of symmetry reduction in epitaxial La₀.₆₇Sr₀.₃₃MnO₃ films (with Radhika Barua and D. Heiman), Physics Faculty Publications (2011)

The magnetic properties of epitaxially grown La0.67Sr0.33MnO3 perovskite thin films were investigated to elucidate an...

 

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Computational design optimization for microfluidic magnetophoresis (with Brian Dennis Plouffe and Shashi Krishna Murthy), Chemical Engineering Faculty Publications (2011)

Current macro- and microfluidic approaches for the isolation of mammalian cells are limited in both...

 

Preprints

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Determining magnetic nanoparticle size distributions from thermomagnetic measurements (with R. S. DiPietro, H. G. Johnson, S. P. Bennett, T. J. Nummy, and D. Heiman), Physics Faculty Publications (2010)

Thermomagnetic measurements are used to obtain the size distribution and anisotropy of magnetic nanoparticles. An...