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Full-Text Articles in Physics
Reducing Leakage Current And Enhancing Polarization In Multiferroic 3d Supernanocomposites By Microstructure Engineering, Erik Enriquez, Ping Lu, Leigang Li, Bruce Zhang, Haiyan Wang, Quanxi Jia, Aiping Chen
Reducing Leakage Current And Enhancing Polarization In Multiferroic 3d Supernanocomposites By Microstructure Engineering, Erik Enriquez, Ping Lu, Leigang Li, Bruce Zhang, Haiyan Wang, Quanxi Jia, Aiping Chen
Computer Science Faculty Publications and Presentations
Multiferroic materials have generated great interest due to their potential as functional device materials. Nanocomposites have been increasingly used to design and generate new functionalities by pairing dissimilar ferroic materials, though the combination often introduces new complexity and challenges unforeseeable in single-phase counterparts. The recently developed approaches to fabricate 3D super-nanocomposites (3D‐sNC) open new avenues to control and enhance functional properties. In this work, we develop a new 3D‐sNC with CoFe2O4 (CFO) short nanopillar arrays embedded in BaTiO3 (BTO) film matrix via microstructure engineering by alternatively depositing BTO:CFO vertically-aligned nanocomposite layers and single-phase BTO layers. This microstructure engineering method allows …
Reducing Leakage Current And Enhancing Polarization In Multiferroic 3d Super-Nanocomposites By Microstructure Engineering, Erik Enriquez, Ping Lu, Leigang Li, Bruce Zhang, Haiyan Wang, Quanxi Jia, Aiping Chen
Reducing Leakage Current And Enhancing Polarization In Multiferroic 3d Super-Nanocomposites By Microstructure Engineering, Erik Enriquez, Ping Lu, Leigang Li, Bruce Zhang, Haiyan Wang, Quanxi Jia, Aiping Chen
Physics and Astronomy Faculty Publications and Presentations
Multiferroic materials have generated great interest due to their potential as functional device materials. Nanocomposites have been increasingly used to design and generate new functionalities by pairing dissimilar ferroic materials, though the combination often introduces new complexity and challenges unforeseeable in single-phase counterparts. The recently developed approaches to fabricate 3D super-nanocomposites (3D‐sNC) open new avenues to control and enhance functional properties. In this work, we develop a new 3D‐sNC with CoFe2O4 (CFO) short nanopillar arrays embedded in BaTiO3 (BTO) film matrix via microstructure engineering by alternatively depositing BTO:CFO vertically-aligned nanocomposite layers and single-phase BTO layers. This microstructure engineering method allows …
One-Pot Synthesis Of Urchin-Like Fepd−Fe3O4 And Their Conversion Into Exchange-Coupled L10−Fepd−Fe Nanocomposite Magnets, Yongsheng Yu, Kewei Sun, Yuan Tian, Xingzhong Li, Matthew J. Kramer, David J. Sellmyer, Jeffrey E. Shield, Shouheng Sun
One-Pot Synthesis Of Urchin-Like Fepd−Fe3O4 And Their Conversion Into Exchange-Coupled L10−Fepd−Fe Nanocomposite Magnets, Yongsheng Yu, Kewei Sun, Yuan Tian, Xingzhong Li, Matthew J. Kramer, David J. Sellmyer, Jeffrey E. Shield, Shouheng Sun
David Sellmyer Publications
We report a one-pot synthesis of urchin-like FePd−Fe3O4 nanocomposites, spherical clusters of FePd nanoparticles (NPs) with spikes of Fe3O4 nanorods (NRs), via controlled thermal decomposition of Fe(CO)5 and reduction of Pd(acac)2. The FePd NPs with sizes between 6 and 9 nm self-aggregate into 60 nm superparticles (SPs), and Fe3O4 NRs grow on the surface of these SPs. Reductive annealing at 500°C converts the FePd−Fe3O4 into exchange-coupled nanocomposites L10−FePd−Fe with their Hc tunable from 0.8 to 2.6 kOe and Ms controlled from 90 to …
Fourier Transform Infrared Spectroscopy And Wide-Angle X-Ray Scattering: Investigations On Polypropylene–Vapor-Grown Carbon Nanofiber Composites, Mircea Chipara, John Hamilton, Alin Cristian Chipara, Tom George, Dorina Magdalena Chipara, Elamin E. Ibrahim, Karen Lozano, David J. Sellmyer
Fourier Transform Infrared Spectroscopy And Wide-Angle X-Ray Scattering: Investigations On Polypropylene–Vapor-Grown Carbon Nanofiber Composites, Mircea Chipara, John Hamilton, Alin Cristian Chipara, Tom George, Dorina Magdalena Chipara, Elamin E. Ibrahim, Karen Lozano, David J. Sellmyer
David Sellmyer Publications
Fourier transform infrared (FTIR) spectroscopy and wide-angle X-ray scattering (WAXS) investigations of isotactic polypropylene (iPP)–vapor-grown carbon nanofiber (VGCNF) composites containing various amounts of VGCNFs ranging between 0 and 20 wt %. are reported. The FTIR investigations were focused on the regularity bands of iPP. The FTIR data indicated a drop in the isotacticity index as the concentration of nanofibers was increased; this suggested a decrease in the crystallinity. WAXS measurements revealed a dominating α1 phase, with a small admixture of γ phase or mesophase. The loading of the polymeric matrix with carbon nanofibers (CNFs) did not induce significant changes …
Holographic Recording In Corona Charged Acrylamide-Based Mfi-Zeolite Photopolymer, Temenujka Yovcheva, Izabela Naydenova, Simeon Sainov, Vincent Toal, Svetlana Mintova
Holographic Recording In Corona Charged Acrylamide-Based Mfi-Zeolite Photopolymer, Temenujka Yovcheva, Izabela Naydenova, Simeon Sainov, Vincent Toal, Svetlana Mintova
Articles
The influence of corona charging on holographic recording in acrylamide-based photopolymer nanocomposite containing MFI zeolite nanoparticles has been studied. The holographic recording was carried out in two different geometries —transmission grating recording and total internal reflection grating recording. During the recording process, the layers were charged in a corona field. It was observed that independently of the corona polarity, in the case of transmission geometry of recording, the corona charging led to a decrease in the diffraction efficiency (DE) of the grating. In the case of the total internal reflection grating, the DE increased in the corona field presence.
Length Scales Of Interactions In Magnetic, Dielectric, And Mechanical Nanocomposites, Ralph Skomski, Balamurugan Balamurugan, Eva Schubert, Axel Enders, David J. Sellmyer
Length Scales Of Interactions In Magnetic, Dielectric, And Mechanical Nanocomposites, Ralph Skomski, Balamurugan Balamurugan, Eva Schubert, Axel Enders, David J. Sellmyer
Axel Enders Publications
It is investigated how figures of merits of nanocomposites are affected by structural and interaction length scales, Aside from macroscopic effects without characteristic lengths scales and atomic-scale quantum-mechanical interactions there are nanoscale interactions that reflect a competition between different energy contributions. We consider three systems, namely dielectric media, carbon-black reinforced rubbers and magnetic composites. In all cases, it is relatively easy to determine effective materials constants, which do not involve specific length scales. Nucleation and breakdown phenomena tend to occur on a nanoscale and yield a logarithmic dependence of figures of merit on the macroscopic system size. Essential system-specific differences …
Photopolymerizable Nanocomposites For Holographic Applications, Elsa Leite
Photopolymerizable Nanocomposites For Holographic Applications, Elsa Leite
Doctoral
Photopolymerizable nanocomposites with good optical properties consisting of an acrylamide based photopolymer and zeolite nanoparticles (Beta, zeolite A, AlPO-18, silicalite-1 and zeolite L) were fabricated and characterized for holographic applications. The colloidal zeolite solutions used in this project were characterized by several techniques including X-Ray Diffraction (XRD), Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM) and Raman spectroscopy to ensure their successful synthesis. The dependence of grating performances in these nanocomposites on recording intensity, spatial frequency and zeolite concentration were studied. It was found that the incorporation of silicalite-1 nanoparticles or a small amount of zeolite A nanoparticles (up to …
Photopolymerizable Nanocomposites For Holographic Recording And Sensor Application, Elsa Leite, Izabela Naydenova, Svetlana Mintova, Louis Leclercq, Vincent Toal
Photopolymerizable Nanocomposites For Holographic Recording And Sensor Application, Elsa Leite, Izabela Naydenova, Svetlana Mintova, Louis Leclercq, Vincent Toal
Articles
Novel nanocomposites consisting of a water soluble acrylamide–based photopolymer and colloidal zeolite nanoparticles of zeolite Beta and zeolite A were prepared. The interactions between the photopolymer components and zeolite nanoparticles in the photopolymerizable nanocomposites were characterized for the first time by 13C NMR and Visible spectroscopy. It was found that the zeolite Beta nanoparticles (up to 5% wt.) behave as a non-inert additive, resulting in an effective increase in layer thickness that causes doubling of the diffraction efficiency of the nanocomposite in comparison to that of the undoped photopolymer. On the other hand, the nanocomposite containing zeolite A nanoparticles showed …
Spectroscopic Investigations On Polypropylene-Carbon Nanofiber Composites: I. Raman And Electron Spin Resonance Spectroscopy, Mircea Chipara, John R. Villarreal, Magdalena Dorina Chipara, Karen Lozano, Alin Cristian Chipara, David J. Sellmyer
Spectroscopic Investigations On Polypropylene-Carbon Nanofiber Composites: I. Raman And Electron Spin Resonance Spectroscopy, Mircea Chipara, John R. Villarreal, Magdalena Dorina Chipara, Karen Lozano, Alin Cristian Chipara, David J. Sellmyer
David Sellmyer Publications
Isotactic polypropylene-vapor grown carbon nanofiber composites containing various fractions of carbon nanofibers, ranging from 0 to 20 wt %, have been prepared. Raman spectroscopy was used to analyze the effect of the dispersion of carbon nanofibers within polypropylene and the interactions between carbon nanofibers and macromolecular chains. The as-recorded Raman spectra have been successfully fitted by a linear convolution of Lorentzian lines. Changes of the Raman lines parameters (position, intensity, width, and area) of polypropylene and carbon nanofibers were analyzed in detail. The Raman spectra of the polymeric matrix—at low concentrations of nanofibers—show important modifications that indicate strong interactions between …
Optical Properties Of Photopolymerisable Nanocomposites Containing Zeolite Nanoparticles, Izabela Naydenova, Tzvetanka Babeva, Elsa Leite, Nitesh Pandey, Temenujka Yovcheva, Svetlana Mintova, Vincent Toal
Optical Properties Of Photopolymerisable Nanocomposites Containing Zeolite Nanoparticles, Izabela Naydenova, Tzvetanka Babeva, Elsa Leite, Nitesh Pandey, Temenujka Yovcheva, Svetlana Mintova, Vincent Toal
Conference Papers
Acrylamide-based photopolymerisable nanocomposites containing three different types of nanozeolites – Si-MFI, AlPO and BEA, were studied. The influence of the porous nanoparticles on the average refractive index, optical scattering, holographic recording properties and shrinkage were characterised.
Nanocomposites For Novel Holographic Applications, Izabela Naydenova, Svetlana Mintova, Suzanne Martin, Vincent Toal
Nanocomposites For Novel Holographic Applications, Izabela Naydenova, Svetlana Mintova, Suzanne Martin, Vincent Toal
Articles
Nanozeolites incorporated into photopolymerizable holographic recording materials can be used for holographic sensing, data storage, and optical systems design.