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Outcome: Dr. Jain and her group at UConn has fabricated nanocomposite films showing (i) magnetoelectric properties: 0-3 type composite thin films comprising of magnetostrictive (magnetic ferrite) nanoparticles embedded in piezoelectric PbZr0.52Ti0.48O3 (PZT) phase and (ii) low-field magnetoresistive properties: 1-3 type composite film with insulating ZnO nanorods embedded in ferromagnetic La0.67Sr0.33MnO3 phase.

Impact: The magnetoelectric (ME) and magnetoresistive composites have potential in device applications, such as in microwave devices, magnetic field sensors, memory devices, transducers, read/write heads, and spintronic devices.

0-3 type and 1-3 type composites, (blue-insulating phase, red-magnetic phase)

Explanation: The ME composites show ME coupling via strain between the CoFe2O4 and piezoelectric phases and the ME voltage coefficient (aE) would depend on the surface area/distribution of the ferrite phase as its agglomeration could lead to high leakage or low aE. It is therefore required to have a uniform distribution of ferrite nanoparticles in PZT film.

In magnetoresistive manganite materials, extrinsic magnetoresistance is obtained due to spin-polarized tunneling of conduction electrons across the interfaces or grains separated by an energy barrier related to magnetic disorder. Thus, manganite composite with insulating material modifies the barrier and influences the tunneling process, thereby changing the field sensitivity in these composites.

Nanocomposite Thin FilmsMenka Jain, University of Connecticut, DMR 1105975

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Conducting substrate

Conducting substrate

AuAu

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HP PX

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Transverse Longitudinal)( 31E )( 33E

Conducting substrate

Conducting substrate

AuAu

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HP PX

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Transverse Longitudinal)( 31E )( 33E

Conducting substrate

Conducting substrate

AuAu

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HP PX

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Transverse Longitudinal)( 31E )( 33E

Conducting substrate

Conducting substrate

AuAu

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HP PX

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Transverse Longitudinal)( 31E )( 33E

The magnetoresistance (MR) values versus magnetic field show a dramatic increase at low fields for a LSMO:ZnO film (LSMO film spin-coated on a ZnO nanorod array) as compared to that of pure LSMO film with field applied parallel to the current. Inset shows the top-view SEM image of LSMO:ZnO film.

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By controlling the concentrations of the dispersed CFO nanoparticles (NPs) in a PZT matrix the transverse (aE31) and longitudinal (aE33) ME coefficients can be tuned.

Published in Advanced Functional Materials, 2012. DOI: 10.1002/adfm.201200489

Nanocomposite Thin FilmsMenka Jain, University of Connecticut, DMR 1105975

Magnetoelectric PZT:CFO films Magnetoresistive LSMO:ZnO film

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Menka Jain, University of Connecticut, DMR 1105975

An integrated education and outreach effort of this project included outreach activities at Gilead School and at UConn {through KAST (Kids are Scientists Too) program} where the 2nd-6th graders received hands on experience in learning physics concepts through small demos.