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Creator | Title | Description | Subject | Date |
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Tiwari, Ashutosh | Modification of high potential, high capacity Li2FeP 2O7 cathode material for lithium ion batteries | Li2FeP2O7 is a newly developed polyanionic cathode material for high performance lithium ion batteries. It is considered very attractive due to its large specific capacity, good thermal and chemical stability, and environmental benignity. However, the application of Li2FeP2O7 is limited by its low i... | | 2012-01-01 |
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Ostafin, Agnes | Monitoring the synthesis and composition analysis of microsilica encapsulated acetylacetonatocarbonyl triphenylphosphinerhodium catalyst by inductively coupled plasma (ICP) techniques | Abstract-A novel technique to monitor the synthesis process of encapsulated acetylacetonatocarbonyl triphenylphosphinerhodium within a microsilica nanoshell has been studied using inductively coupled plasma (ICP) techniques. Nanospheres sized around 50-100 nm were obtained and ICP was used to quanti... | | 2006 |
3 |
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Liu, Feng | Computational R&D for industrial applications | Recent advances in high-speed supercomputer and computational algorithms have brought us into a new era of computational materials science. These advances make it possible to investigate many existing materials systems that were previously considered intractable and also predict and design novel mat... | Computational materials science | 2005 |
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Tiwari, Ashutosh | Characterization of Li7La3Zr2O 12 thin films prepared by pulsed laser deposition | A pulsed laser deposition system was employed to fabricate thin films of Li7La3Zr2O12 solid electrolyte. The deposition process was carried out at room-temperature, resulting in amorphous films. These as-deposited films had a large optical band gap of 5.13 eV, and exhibited a lithium-ion conductivit... | | 2012-01-01 |
5 |
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Liu, Feng | Bending of nanoscale thin Si film induced by growth of Ge islands: hut vs. dome | We perform atomistic simulations to compute bending of freestanding nanoscale thin Si film induced by strained Ge islands. We show that a larger Ge dome island can induce smaller bending than a smaller hut island and explain the surprising experimental observation for growth of Ge islands on pattern... | Bending; Nanoscale thin Si film; Ge islands; Hut islands; Dome islands; Atomistic simulations | 2004 |
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Tiwari, Ashutosh | Oxides for spintronics: a review of engineered materials for spin injection | In this article we have reviewed the role of oxides in spintronics research, and specifically how these materials stand to further improve the efficiencies and capabilities of spin injection for active spintronic device development. The use of oxides in spintronics is advantageous in that they are s... | | 2014-01-01 |
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Tiwari, Ashutosh | Garnet-type Li7La3Zr2O12 electrolyte prepared by a solution-based technique for lithium ion battery | High quality garnet-type Li7La3Zr2O12 solid electrolyte was synthesized using a solution-based technique. The electrolyte pellets were sintered at 900 oC, resulting in tetragonal phase, which then transformed to cubic phase after annealing at 1230 oC. The ionic conductivity of both phases was studie... | | 2012-01-01 |
8 |
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Tiwari, Ashutosh | Electrical transport in ultrathin NdNiO3 films | Electrical transport properties in ultrathin NdNiO3 films grown on single crystal LaAlO3 (001) substrate were characterized. Films with thicknesses ranging from 0.6 nm to 12 nm were grown using a pulsed laser technique. Four probe resistivity as a function of temperature measurements indicated a str... | | 2012-01-01 |
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Tiwari, Ashutosh | Growth of epitaxial ZnO films on Si(111) | Epitaxial ZnO films have been grown on Si(l 11) substrates by employing a A1N buffer layer during a pulsed laser-deposition process. The epitaxial structure of A1N on Si(l 11) substrate provides a template for ZnO growth. The resultant films are evaluated by transmission electron microscopy, x-ray ... | Buffer layers; Aluminum nitride; Silicon substrate | 2002 |
10 |
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Tiwari, Ashutosh | Pulsed laser deposition and characterization of Zn1-xMnxO films | Here we present our results of structural, optical, and magnetic measurements of Zn1-xMnxO thin films. These films were grown epitaxially on (0001) sapphire substrates by using pulsed laser deposition technique. The maximum Mn content (x=0.36) is found to be much higher than allowed by thermal equl... | | 2002 |
11 |
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Liu, Feng | First-principles study of impurity segregation in edge dislocations in Si | Using ab initio calculations, the segregation of As, Ga, and Ge atoms in the core regions of perfect edge dislocations in Si is examined. When all nearest neighbors of an impurity are Si atoms, As favors the core site at maximum compression and has a segregation energy of 0.25 eV/atom. Ga and Ge im... | First-principles; Impurity segregation; Edge dislocations | 2000-01 |
12 |
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Tiwari, Ashutosh | Self-aligned passivated copper interconnects: a novel technique for making interconnections in ultra large scale integration device applications | We have developed a technique to grow self-aligned epitaxial Cu/MgO films on Si (100) using a Pulsed Laser Deposition Method. In this method we deposit a uniform film of Cu/Mg (5-7%) alloy over Si (100) at room temperature using TiN as an intermediate buffer layer. As a result of HRTEM (with spatial... | Passivated copper interconnects; Diffusion barriers; Copper diffusion; Tantalum nitride | 2002 |
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Tiwari, Ashutosh | Epitaxial growth of ZnO films on Si(111) | In this paper, we report the growth of ZnO films on silicon substrates using a pulsed laser deposition technique. These films were deposited on Si(111) directly as well as by using thin buffer layers of AlN and GaN. All the films were found to have c-axis-preferred orientation aligned with normal to... | Buffer layers; Aluminum nitride; Silicon substrate; Biaxial strain | 2002 |
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Liu, Feng | Pattern formation on silicon-on-insulator | The strain driven self-assembly of faceted Ge nanocrystals during epitaxy on Si(001) to form quantum dots (QDs) is by now well known. We have also recently provided an understanding of the thermodynamic driving force for directed assembly of QDs on bulk Si (extendable to other QD systems) based on ... | Pattern formation; Silicon-on-insulator; Strain driven; Faceted Ge nanocrystals; Si(001); Directed assembly | 2005 |
15 |
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Tiwari, Ashutosh | Epitaxial growth of magnetic nickel nanodots by pulsed laser deposition | Epitaxial nickel magnetic nanodots were obtained by pulsed laser deposition (PLD) technique on Si (100) substrate using epitaxial TiN film as the template. Characterization methods include: high-resolution transmission electron microscopy (HRTEM), scanning transmission electron microscopy (STEM) Z-... | Nanodots; TiN; Nickel | 2003 |
16 |
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Tiwari, Ashutosh | Ferromagnetism in Co doped CeO2: observation of giant magnetic moment with a high Curie temperature | We report room temperature ferromagnetism in single crystal Ce1−xCoxO2−δ (x≤0.05) films deposited on a LaAlO3(001) substrate. Films were grown by a pulsed laser deposition technique and were thoroughly characterized using x-ray diffraction, high-resolution transmission electron microscopy cou... | CeO2; Cobalt | 2006 |
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Liu, Feng | Magnetization on vicinal ferromagnetic surfaces | Using Ising model Monte Carlo simulations, we show a strong dependence of surface magnetization on surface miscut angle. For ferromagnetic surfaces, when surface spin exchange coupling is larger than that of the bulk, the surface magnetic ordering temperature decreases, toward the bulk Curie tempera... | Vicinal ferromagnetic surfaces; Surface magnetization; Surface miscut angle | 1997 |
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Stringfellow, Gerald B. | Mechanism for liquid phase epitaxial growth of nonequilibrium compositions producing a coherent interface | A model is presented for growth by so-called composition pulling, wherein an epitaxial deposit grows coherently but with a composition different from that which would be in bulk equilibrium with the liquid phase from which growth occurs. The breakdown of coherent growth occurs when a dislocation nuc... | Lattice-matching overgrowths; Composition pulling; Dislocation interface | 1977 |
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Tiwari, Ashutosh | Copper diffusion characteristics in single crystal and polycrystalline TaN | TaN has become a very promising diffusion barrier material for Cu interconnections, due to the high thermal stability requirement and thickness limitation for next generation ULSI devices. TaN has a variety of phases and Cu diffusion characteristics vary with different phases and microstructures. We... | Diffusion barriers; Copper diffusion; Tantalum nitride | 2003 |
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Tiwari, Ashutosh | Epitaxial growth and properties of Zn1-xVxO diluted magnetic semiconductor thin films | Here we report systematic studies on the epitaxial growth and properties of Zn1−xVxO[x=0.001-0.2] thin films deposited onto sapphire c-plane single crystals. The thin films were deposited using pulsed laser deposition technique and were found to be epitaxial in nature. X-ray diffraction and high ... | ZnO; Vanadium | 2005 |
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Tiwari, Ashutosh | Nanostructured DLC-Ag composites for biomedical applications | We have synthesized novel diamondlike carbon coatings with silver nanoparticles embedded into the DLC film. The size of silver nanoparticles that are confined into layered structures has been varied from 5 nm to 50 nm using an ingenious pulsed laser deposition technique. The size of nanoparticles wa... | Diamondlike carbon coatings; Nanocrystals | 2003 |
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Liu, Feng | Pattern formation via a two-step faceting transition on vicinal Si(111) surfaces | We demonstrate a self-organized pattern formation on vicinal Si(l 11) surfaces that are miscut toward the [211] direction. All the patterns, consisting of a periodic array of alternating (7x7) reconstructed terraces and step-bunched facets, have the same periodicity and facet structure, independent ... | Pattern formation; Faceting transition; Vicinal Si(111); Miscut | 2001 |
23 |
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Tiwari, Ashutosh | Single crystal TaN thin films on TiN/Si heterostructure | We have successfully grown epitaxial cubic (Bl-NaCl structure) tantalum nitride films on Si (100) and (111) substrate using a pulsed laser deposition technique. A thin layer of titanium nitride was used as a buffer medium. We characterized these films using X-ray diffraction, high resolution transmi... | Tantalum nitride; Diffusion barriers; Copper diffusion | 2002 |
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Tiwari, Ashutosh | Observation of the inverse spin hall effect in ZnO thin films: an all-electrical approach to spin injection and detection | The inverse spin Hall effect (ISHE) is a newly discovered, quantum mechanical phenomenon where an applied spin current results in the generation of an electrical voltage in the transverse direction. It is anticipated that the ISHE can provide a more simple way of measuring spin currents in spintroni... | | 2014-01-01 |
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Stringfellow, Gerald B. | Radiative pair transitions in p-type ZnSe:Cu crystals | Shallow levels with an ionization energy of 0.012 eV play an important role in the photoelectronic properties of p-type ZnSe:Cu crystals. These levels exhibit the characteristics of the higher-lying member of an imperfection pair involved in luminescence emission, as well as of a trap determining lo... | Ionization energy; Luminescence emission; Crystals | 1968 |