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Articles 1 - 5 of 5

Full-Text Articles in Chemistry

One-Pot Synthesis In Polyamines For Preparation Of Water-Soluble Magnetite Nanoparticles With Amine Surface Reactivity, Haiou Qu, Hui Ma, Aurélien Riviere, Weilie Zhou, Charles J. O'Connor Jan 2012

One-Pot Synthesis In Polyamines For Preparation Of Water-Soluble Magnetite Nanoparticles With Amine Surface Reactivity, Haiou Qu, Hui Ma, Aurélien Riviere, Weilie Zhou, Charles J. O'Connor

Chemistry Faculty Publications

Magnetite nanoparticles with hydrophilic surface coating are prepared in polyamine solvents. The resulting products are highly stable in polar solvent. The surface amine groups are available for secondary reactions.


Magnetoelectric Effect In Ain/Cofe Bi-Layer Thin Film Composites, S Narendra Babu, Seong-Gi Min, Amin Yourdkhani, Gabriel Caruntu, Leszek M. Malkinski Jan 2012

Magnetoelectric Effect In Ain/Cofe Bi-Layer Thin Film Composites, S Narendra Babu, Seong-Gi Min, Amin Yourdkhani, Gabriel Caruntu, Leszek M. Malkinski

Chemistry Faculty Publications

The present work is aimed at fabricating bi-layer aluminum nitride (AlN)/cobalt iron (CoFe) magnetoelectric (ME) thin films using reactive rf/dc magnetron sputtering. A systematic study on structural, morphological, piezoelectric, magnetic and magnetoelectric properties is undertaken. Except for AlN and CoFe, no other phases were detected with the layer thicknesses measured at160 and 130 nm, respectively. The rms roughness measured was around 2.096 nm for AlN and 1.806 nm for CoFe. The bi-layer thin film exhibited both good piezoelectricity and ferromagnetism, as well as ME effect. A 52% change observed in the piezoelectric signal, measured using magnetic field assisted piezoresponse force …


Dynamics And Collective State Of Ordered Magnetic Nanoparticles In Mesoporous Systems, Jose M. Vargas, Abhishek Srivastava, Ezra Garza, Gabriel Caruntu, Amin Yourdkhani, Leonard Spinu Jan 2012

Dynamics And Collective State Of Ordered Magnetic Nanoparticles In Mesoporous Systems, Jose M. Vargas, Abhishek Srivastava, Ezra Garza, Gabriel Caruntu, Amin Yourdkhani, Leonard Spinu

Chemistry Faculty Publications

In this paper we present a study of superparamagnetic and superspin glass states of magnetic nanoparticles confined in mesoporous templates. Characterization utilizes dynamic magnetization techniques, ac susceptibility, and ferromagnetic resonance, in addition to dc magnetization curves. In order to differentiate between the intrinsic and collective properties, we considered three magnetic nanoparticles systems with comparable size, shape, and crystallinity but with different intrinsic magnetocrystalline anisotropy. Further, confinement effects were studied by considering three different geometries of nanoparticles. The effect of the geometrical confinement and intrinsic anisotropy of the nanoparticles are discussed based on known theoretical predictions.


Synthesis And Piezoelectric Response Of Cubic And Spherical Linbo3 Nanocrystals, Debasish Mohanty, Girija S. Chaubey, Amin Yourdkhani, Shiva Adireddy, Gabriel Caruntu, John B. Wiley Jan 2012

Synthesis And Piezoelectric Response Of Cubic And Spherical Linbo3 Nanocrystals, Debasish Mohanty, Girija S. Chaubey, Amin Yourdkhani, Shiva Adireddy, Gabriel Caruntu, John B. Wiley

Chemistry Faculty Publications

Methods have been developed for the shape-selective synthesis of ferroelectric LiNbO3 nanoparticles. Decomposition of the single-source precursor, LiNb(O-Et)6, in the absence of surfactants, can reproducibly lead to either cube- or sphere-like nanoparticles. X-Ray diffraction shows that the LiNbO3 nanoparticles are rhombohedral (R3c). Sample properties were examined by piezoresponse force microscopy (PFM) and Raman where both sets of nanoparticles exhibit ferroelectricity. The longitudinal piezoelectric coefficients, d33, varied with shape where the largest value was exhibited in the nanocubes (17 pm V21 for the cubes versus 12 pm V21 for spheres).


Dynamics And Collective State Of Ordered Magnetic Nanoparticles In Mesoporous Systems, Jose M. Vargas, Abhishek Srivastava, Ezra Garza, Amin Yourdkhani, Gabriel Caruntu, Leonard Spinu Jan 2012

Dynamics And Collective State Of Ordered Magnetic Nanoparticles In Mesoporous Systems, Jose M. Vargas, Abhishek Srivastava, Ezra Garza, Amin Yourdkhani, Gabriel Caruntu, Leonard Spinu

Chemistry Faculty Publications

In this paper we present a study of superparamagnetic and superspin glass states of magnetic nanoparticles confined in mesoporous templates. Characterization utilizes dynamic magnetization techniques, ac susceptibility, and ferromagnetic resonance, in addition to dc magnetization curves. In order to differentiate between the intrinsic and collective properties, we considered three magnetic nanoparticles systems with comparable size, shape, and crystallinity but with different intrinsic magnetocrystalline anisotropy. Further, confinement effects were studied by considering three different geometries of nanoparticles. The effect of the geometrical confinement and intrinsic anisotropy of the nanoparticles are discussed based on known theoretical predictions.