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Articles 31 - 60 of 60

Full-Text Articles in Engineering

Phase Formation And Hydrogen Ordering In Yttrium-Hydrogen System, Ke Wang, Jason Hattrick-Simpers, Leonid Bendersky Mar 2015

Phase Formation And Hydrogen Ordering In Yttrium-Hydrogen System, Ke Wang, Jason Hattrick-Simpers, Leonid Bendersky

Jason R. Hattrick-Simpers

No abstract provided.


Combinatorial Study Of Ni-Ti-Pt Ternary Metal Gate Electrodes On Hfo2 For The Advanced Gate Stack, K.-S. Chang, M. Green, J. Suehle, E. Vogel, H. Xiong, Jason Hattrick-Simpers, I. Takeuchi, O. Famodu, K. Ohmori, P. Ahmet, T. Chikyow, P. Majhi, B.-H. Lee, M. Gardner Mar 2015

Combinatorial Study Of Ni-Ti-Pt Ternary Metal Gate Electrodes On Hfo2 For The Advanced Gate Stack, K.-S. Chang, M. Green, J. Suehle, E. Vogel, H. Xiong, Jason Hattrick-Simpers, I. Takeuchi, O. Famodu, K. Ohmori, P. Ahmet, T. Chikyow, P. Majhi, B.-H. Lee, M. Gardner

Jason R. Hattrick-Simpers

The authors have fabricated combinatorial Ni–Ti–Pt ternary metal gate thin film libraries on HfO2 using magnetron co-sputtering to investigate flatband voltage shift (ΔVfb) , work function (Φm) , and leakage current density (JL) variations. A more negative ΔVfb is observed close to the Ti-rich corner than at the Ni- and Pt-rich corners, implying smaller Φm near the Ti-rich corners and higher Φm near the Ni- and Pt-rich corners. In addition, measured JL values can be explained consistently with the observed Φm variations. Combinatorial methodologies prove to be useful in surveying the large compositional space of ternary alloymetal gate electrode systems.


Interphase Exchange Coupling In Fe/Sm-Co Bilayers With Gradient Fe Thickness, Ming-Hui Yu, Jason Hattrick-Simpers, Ichiro Takeuchi, Jing Li, Z. Wang, J. Liu, S. Lofland, Somdev Tyagi, J. Freeland, D. Giubertoni, M. Bersani, M. Anderle Mar 2015

Interphase Exchange Coupling In Fe/Sm-Co Bilayers With Gradient Fe Thickness, Ming-Hui Yu, Jason Hattrick-Simpers, Ichiro Takeuchi, Jing Li, Z. Wang, J. Liu, S. Lofland, Somdev Tyagi, J. Freeland, D. Giubertoni, M. Bersani, M. Anderle

Jason R. Hattrick-Simpers

We have fabricated Fe∕Sm–Co bilayers with gradient Fe thicknesses in order to systematically study the dependence of exchange coupling on the thickness of the Fe layer. The Fe layer was deposited at two different temperatures (150 and 300°C) to study the effect of deposition temperature on the exchange coupling. Magneto-optical Kerr effect and x-ray magnetic circular dichroism (XMCD) have been employed as nondestructive rapid characterization tools to map the magnetic properties of the gradient samples. Systematic enhancement in exchange coupling between the soft layer and the hard layer is observed as the soft layer thickness is decreased. Separate exchange couplings …


High-Throughput Characterization Of Shape Memory Thin Films Using Automated Temperature-Dependent Resistance Measurements, Sigurd Thienhaus, Christiane Zamponi, Holger Rumpf, Jason Hattrick-Simpers, Ichiro Takeuchi, Alfred Ludwig Mar 2015

High-Throughput Characterization Of Shape Memory Thin Films Using Automated Temperature-Dependent Resistance Measurements, Sigurd Thienhaus, Christiane Zamponi, Holger Rumpf, Jason Hattrick-Simpers, Ichiro Takeuchi, Alfred Ludwig

Jason R. Hattrick-Simpers

No abstract provided.


High-Throughput Screening Of Shape Memory Alloy Thin-Film Spreads Using Nanoindentation, Arpit Dwivedi, Thomas Wyrobek, Oden Warren, Jason Hattrick-Simpers, Olubenga Famodu, Ichiro Takeuchi Mar 2015

High-Throughput Screening Of Shape Memory Alloy Thin-Film Spreads Using Nanoindentation, Arpit Dwivedi, Thomas Wyrobek, Oden Warren, Jason Hattrick-Simpers, Olubenga Famodu, Ichiro Takeuchi

Jason R. Hattrick-Simpers

We have demonstrated the utility of nanoindentation as a rapid characterization tool for mapping shape memoryalloy compositions in combinatorial thin-film libraries. Nanoindentation was performed on Ni–Mn–Al ternary composition spreads. The indentation hardness and the reduced elastic modulus were mapped across a large fraction of the ternary phase diagram. The large shape memoryalloy composition region, located around the Heusler composition (Ni2MnAl), was found to display significant departure in these mechanical properties from the rest of the composition spread. In particular, the modulus and the hardness values are lower for the martensite region than those of the rest of the phase diagram.


The Materials Super Highway: Integrating High-Throughput Experimentation Into Mapping The Catalysis Materials Genome, Jason Hattrick-Simpers, Cun Wen, Jochen Lauterbach Mar 2015

The Materials Super Highway: Integrating High-Throughput Experimentation Into Mapping The Catalysis Materials Genome, Jason Hattrick-Simpers, Cun Wen, Jochen Lauterbach

Jason R. Hattrick-Simpers

No abstract provided.


A Semi-Empirical Model For Tilted-Gun Planar Magnetron Sputtering Accounting For Chimney Shadowing, Johnathan Bunn, C. Metting, Jason Hattrick-Simpers Mar 2015

A Semi-Empirical Model For Tilted-Gun Planar Magnetron Sputtering Accounting For Chimney Shadowing, Johnathan Bunn, C. Metting, Jason Hattrick-Simpers

Jason R. Hattrick-Simpers

No abstract provided.


Note: A Simple Thermal Gradient Annealing Unit For The Treatment Of Thin Films, C. Metting, Johnathan Bunn, Ellen Underwood, Yihao Zhu, G. Koley, T. Crawford, Jason Hattrick-Simpers Mar 2015

Note: A Simple Thermal Gradient Annealing Unit For The Treatment Of Thin Films, C. Metting, Johnathan Bunn, Ellen Underwood, Yihao Zhu, G. Koley, T. Crawford, Jason Hattrick-Simpers

Jason R. Hattrick-Simpers

A gradient annealing cell has been developed for the high-throughput study of thermalannealing effects on thin-film libraries in different environments. The inexpensive gradientannealing unit permits temperature gradients as large as 28 °C/mm and can accommodate samples ranging in length from 13 mm to 51 mm. The system was validated by investigating the effects of annealing temperature on the crystallinity, resistivity, and transparency of tin-doped indium oxide deposited on a glass substrate by magnetron sputtering. The unit developed in this work will permit the rapid optimization of materials properties such as crystallinity, homogeneity, and conductivity across a variety of applications.


Combinatorial Approach To Turbine Bond Coat Discovery, Christopher Metting, Johnathan Bunn, Ellen Underwood, Stephen Smoak, Jason Hattrick-Simpers Mar 2015

Combinatorial Approach To Turbine Bond Coat Discovery, Christopher Metting, Johnathan Bunn, Ellen Underwood, Stephen Smoak, Jason Hattrick-Simpers

Jason R. Hattrick-Simpers

No abstract provided.


Recent Developments In Thermoelectric Metrology At Nist, W. Wong-Ng, J. Martin, E. Thomas, M. Otani, N. Lowhorn, M. Green, G. Liu, Y. Yan, Jason Hattrick-Simpers, T. Tran Mar 2015

Recent Developments In Thermoelectric Metrology At Nist, W. Wong-Ng, J. Martin, E. Thomas, M. Otani, N. Lowhorn, M. Green, G. Liu, Y. Yan, Jason Hattrick-Simpers, T. Tran

Jason R. Hattrick-Simpers

No abstract provided.


Exploration Of Magnetoelectric Thin-Film Sensors Using Supperlattice Composition Spreads, K.-S. Chang, M. Aronova, C. Gao, C. Lin, Jason Hattrick-Simpers, M. Murakami, I. Takeuchi Mar 2015

Exploration Of Magnetoelectric Thin-Film Sensors Using Supperlattice Composition Spreads, K.-S. Chang, M. Aronova, C. Gao, C. Lin, Jason Hattrick-Simpers, M. Murakami, I. Takeuchi

Jason R. Hattrick-Simpers

No abstract provided.


Combinatorial Investigation Of Ferromagnetic Shape-Memory Alloys In The Ni-Mn-Al Ternary System Using A Composition Spread Technique, Olugbenga Famodu, Jason Hattrick-Simpers, Maria Aronova, Kao-Shou Chang, Makoto Murakami, Manfred Wuttig, Teiko Okazaki, Yasubumi Furuya, Lee Knauss, Leonid Bendersky, Frank Biaricaniello, Ichiro Takeuchi Mar 2015

Combinatorial Investigation Of Ferromagnetic Shape-Memory Alloys In The Ni-Mn-Al Ternary System Using A Composition Spread Technique, Olugbenga Famodu, Jason Hattrick-Simpers, Maria Aronova, Kao-Shou Chang, Makoto Murakami, Manfred Wuttig, Teiko Okazaki, Yasubumi Furuya, Lee Knauss, Leonid Bendersky, Frank Biaricaniello, Ichiro Takeuchi

Jason R. Hattrick-Simpers

No abstract provided.


Characterization Of Magnetic Degradation Mechanism In A High Neutron-Flux Environment, Adib Samin, Jie Qiu, Jason Hattrick-Simpers, Liyang Dai-Hattrick, Yuan Zheng, Lei Cao Mar 2015

Characterization Of Magnetic Degradation Mechanism In A High Neutron-Flux Environment, Adib Samin, Jie Qiu, Jason Hattrick-Simpers, Liyang Dai-Hattrick, Yuan Zheng, Lei Cao

Jason R. Hattrick-Simpers

No abstract provided.


Observation Of Phase Transitions In Hydrogenated Yttrium Films Via Normalized Infrared Emissivity, Jason Hattrick-Simpers, Ke Wang, Lei Cao, Chun Chiu, Edwin Heilweil, Robert Downing, Leonid Bendersky Mar 2015

Observation Of Phase Transitions In Hydrogenated Yttrium Films Via Normalized Infrared Emissivity, Jason Hattrick-Simpers, Ke Wang, Lei Cao, Chun Chiu, Edwin Heilweil, Robert Downing, Leonid Bendersky

Jason R. Hattrick-Simpers

No abstract provided.


Combinatorial Study Of Thin Film Metal Hydride By Prompt Gamma Activation Analysis, L. Cao, Jason Hattrick-Simpers, R. Bindel, R. Bindel, B. Tomlin, R. Zeisler, R. Paul, L. Bendersky, R. Downing Mar 2015

Combinatorial Study Of Thin Film Metal Hydride By Prompt Gamma Activation Analysis, L. Cao, Jason Hattrick-Simpers, R. Bindel, R. Bindel, B. Tomlin, R. Zeisler, R. Paul, L. Bendersky, R. Downing

Jason R. Hattrick-Simpers

No abstract provided.


Combinatorial Search Of Thermoelastic Shape-Memory Alloys With Extremely Small Hysteresis Width, Jun Cui, Yong Chu, Olugbenga Famodu, Yasubumi Furuya, Jason Hattrick-Simpers, Richard James, Alfred Ludwig, Sigurd Thienhaus, Manfred Wuttig, Zhiyong Zhang, Ichiro Takeuchi Mar 2015

Combinatorial Search Of Thermoelastic Shape-Memory Alloys With Extremely Small Hysteresis Width, Jun Cui, Yong Chu, Olugbenga Famodu, Yasubumi Furuya, Jason Hattrick-Simpers, Richard James, Alfred Ludwig, Sigurd Thienhaus, Manfred Wuttig, Zhiyong Zhang, Ichiro Takeuchi

Jason R. Hattrick-Simpers

No abstract provided.


Enhanced Dielectric Properties In Single Crystal-Like Bifeo3 Thin Films Grown By Flux-Mediated Epitaxy, S.-H. Lim, M. Murakami, J. Yang, S.-Y. Young, Jason Hattrick-Simpers, M. Wuttig, L. Salamanca-Riba, I. Takeuchi Mar 2015

Enhanced Dielectric Properties In Single Crystal-Like Bifeo3 Thin Films Grown By Flux-Mediated Epitaxy, S.-H. Lim, M. Murakami, J. Yang, S.-Y. Young, Jason Hattrick-Simpers, M. Wuttig, L. Salamanca-Riba, I. Takeuchi

Jason R. Hattrick-Simpers

We have fabricated single crystal-like BiFeO3 (BFO) thin films by flux-mediated epitaxy using pulsed laser deposition(PLD). The Bi–Cu–O flux composition and its thickness were optimized using composition spread, thickness gradient, and temperature gradient libraries. The optimized BFO thin films grown with this technique showed larger grain size of ∼2μm and higher dielectric constant in the range of 260–340 than those for standard PLD grown films. In addition, the leakage current density of the films was reduced by two orders of magnitude compared to that of standard PLD grown films.


Optical Cell For Combinatorial In Situ Raman Spectroscopic Measurements Of Hydrogen Storage Materials At High Pressures And Temperatures, Jason Hattrick-Simpers, Wilbur Hurst, Sesha Srinivasan, James Maslar Mar 2015

Optical Cell For Combinatorial In Situ Raman Spectroscopic Measurements Of Hydrogen Storage Materials At High Pressures And Temperatures, Jason Hattrick-Simpers, Wilbur Hurst, Sesha Srinivasan, James Maslar

Jason R. Hattrick-Simpers

An optical cell is described for high-throughput backscattering Raman spectroscopic measurements of hydrogen storagematerials at pressures up to 10 MPa and temperatures up to 823 K. High throughput is obtained by employing a 60 mm diameter × 9 mm thick sapphire window, with a corresponding 50 mm diameter unobstructed optical aperture. To reproducibly seal this relatively large window to the cell body at elevated temperatures and pressures, a gold o-ring is employed. The sample holder-to-window distance is adjustable, making this cell design compatible with optical measurement systems incorporating lenses of significantly different focal lengths, e.g., microscope objectives and single element …


Self-Healing Catalysts: Co3O4 Nanorods For Fischer-Tropsch Synthesis, Cun Wen, Darrius Dunbar, Xin Zhang, Jochen Lauterbach, Jason Hattrick-Simpers Mar 2015

Self-Healing Catalysts: Co3O4 Nanorods For Fischer-Tropsch Synthesis, Cun Wen, Darrius Dunbar, Xin Zhang, Jochen Lauterbach, Jason Hattrick-Simpers

Jason R. Hattrick-Simpers

We combine kinetic and spectroscopic data to demonstrate the concept of a self-healing catalyst, which effectively eliminates the need for catalyst regeneration. The observed self-healing is triggered by controlling the crystallographic orientation at the catalyst surface.


Tunable Multiferroic Properties In Nanocomposite Pbtio3-Cofe2O4 Epitaxial Thin Films, M. Murakami, K.-S. Chang, M. Aronova, C.-L. Lin, Ming Yu, Jason Hattrick-Simpers, M. Wuttig, I. Takeuchi, C. Gao, B. Hu, S. Lofland, L. Knauss, L. Bendersky Mar 2015

Tunable Multiferroic Properties In Nanocomposite Pbtio3-Cofe2O4 Epitaxial Thin Films, M. Murakami, K.-S. Chang, M. Aronova, C.-L. Lin, Ming Yu, Jason Hattrick-Simpers, M. Wuttig, I. Takeuchi, C. Gao, B. Hu, S. Lofland, L. Knauss, L. Bendersky

Jason R. Hattrick-Simpers

We report on the synthesis of PbTiO3–CoFe2O4 multiferroic nanocomposites and continuous tuning of their ferroelectric and magnetic properties as a function of the average composition on thin-film composition spreads. The highest dielectric constant and nonlinear dielectric signal was observed at (PbTiO3)85–(CoFe2O4)15, where robust magnetism was also observed. Transmission electron microscopy revealed a pancake-shaped epitaxial nanostructure of PbTiO3 on the order of 30 nm embedded in the matrix of CoFe2O4 at this composition. Composition dependent ferroics properties observed here indicate that there is considerable interdiffusion of cations into each other.


Effects Of Neutron And Gamma Radiation On Lithium-Ion Batteries, Jie Qiu, Dandan He, Mingzhai Sun, Shimeng Li, Cun Wen, Jason Hattrick-Simpers, Yuan Zheng, Lei Cao Mar 2015

Effects Of Neutron And Gamma Radiation On Lithium-Ion Batteries, Jie Qiu, Dandan He, Mingzhai Sun, Shimeng Li, Cun Wen, Jason Hattrick-Simpers, Yuan Zheng, Lei Cao

Jason R. Hattrick-Simpers

No abstract provided.


Synthesis Of Mono-Disperse Cofe Alloy Nanoparticles With High Activity Toward Nabh4 Hydrolysis, Cun Wen, Xin Zhang, Samuel Lofland, Jochen Lauterbach, Jason Hattrick-Simpers Mar 2015

Synthesis Of Mono-Disperse Cofe Alloy Nanoparticles With High Activity Toward Nabh4 Hydrolysis, Cun Wen, Xin Zhang, Samuel Lofland, Jochen Lauterbach, Jason Hattrick-Simpers

Jason R. Hattrick-Simpers

No abstract provided.


A Combinatorial Characterization Scheme For High-Throughput Investigations Of Hydrogen Storage Materials, Jason Hattrick-Simpers, Zhuopeng Tan, Hiroyuki Oguchi, Chun Chiu, Edwin Heilweil, James Maslar, Leonid Bendersky Mar 2015

A Combinatorial Characterization Scheme For High-Throughput Investigations Of Hydrogen Storage Materials, Jason Hattrick-Simpers, Zhuopeng Tan, Hiroyuki Oguchi, Chun Chiu, Edwin Heilweil, James Maslar, Leonid Bendersky

Jason R. Hattrick-Simpers

No abstract provided.


An Infrared Imaging Method For High-Throughput Combinatorial Investigation Of Hydrogenation-Dehydrogenation And New Phase Formation Of Thin Films, H. Oguchi, Jason Hattrick-Simpers, I. Takeuchi, E. Heilweil, L. Bendersky Mar 2015

An Infrared Imaging Method For High-Throughput Combinatorial Investigation Of Hydrogenation-Dehydrogenation And New Phase Formation Of Thin Films, H. Oguchi, Jason Hattrick-Simpers, I. Takeuchi, E. Heilweil, L. Bendersky

Jason R. Hattrick-Simpers

We have developed an infrared imaging setup enabling in situ infrared images to be acquired, and expanded on capabilities of an infrared imaging as a high-throughput screening technique, determination of a critical thickness of a Pd capping layer which significantly blocks infrared emission from below, enhancement of sensitivity to hydrogenation and dehydrogenation by normalizing raw infrared intensity of a Mg thin film to an inert reference, rapid and systematic screening of hydrogenation and dehydrogenation properties of a Mg–Ni composition spread covered by a thickness gradient Pd capping layer, and detection of formation of a Mg2Si phase in a Mg thin …


Multimode Quantitative Scanning Microwave Microscopy Of In Situ Grown Epitaxial Ba1-XSrXTio3 Composition Spreads, K. Chang, M. Aronova, O. Famodu, I. Takeuchi, S. Lofland, Jason Hattrick-Simpers, H. Chang Mar 2015

Multimode Quantitative Scanning Microwave Microscopy Of In Situ Grown Epitaxial Ba1-XSrXTio3 Composition Spreads, K. Chang, M. Aronova, O. Famodu, I. Takeuchi, S. Lofland, Jason Hattrick-Simpers, H. Chang

Jason R. Hattrick-Simpers

We have performed variable-temperature multimode quantitative microwavemicroscopy of in situepitaxial Ba1−xSrxTiO3 thin-film composition spreads fabricated on (100) LaA1O3 substrates. Dielectric properties were mapped as a function of continuously varying composition from BaTiO3 to SrTiO3. We have demonstrated nondestructive temperature-dependent dielectric characterization of local thin-film regions. Measurements are simultaneously taken at multiple resonant frequencies of the microscope cavity. The multimode measurements allow frequency dispersion studies. We observe strong composition-dependent dielectric relaxation in Ba1−xSrxTiO3 at microwave frequencies.


One-Step Production Of Long-Chain Hydrocarbons From Waste-Biomass-Derived Chemicals Using Bi-Functional Heterogeneous Catalysts, Cun Wen, Elizabeth Barrow, Jason Hattrick-Simpers, Jochen Lauterbach Mar 2015

One-Step Production Of Long-Chain Hydrocarbons From Waste-Biomass-Derived Chemicals Using Bi-Functional Heterogeneous Catalysts, Cun Wen, Elizabeth Barrow, Jason Hattrick-Simpers, Jochen Lauterbach

Jason R. Hattrick-Simpers

n this study, we demonstrate the production of long-chain hydrocarbons (C8+) from 2-methylfuran (2MF) and butanal in a single step reactive process by utilizing a bi-functional catalyst with both acid and metallic sites. Our approach utilizes a solid acid for the hydroalkylation function and as a support as well as a transition metal as hydrodeoxygenation catalyst. A series of solid acids was screened, among which MCM-41 demonstrated the best combination of activity and stability. Platinum nanoparticles were then incorporated into the MCM-41. The Pt/MCM-41 catalyst showed 96% yield for C8+ hydrocarbons and the catalytic performance was stable over four reaction …


Electrochemical Generation Of Superoxide In Room-Temperature Ionic Liquids, Inas Alnashef, Matthew Leonard, Matthew Kittle, Michael Matthews, John Weidner Sep 2014

Electrochemical Generation Of Superoxide In Room-Temperature Ionic Liquids, Inas Alnashef, Matthew Leonard, Matthew Kittle, Michael Matthews, John Weidner

Michael A. Matthews

We have demonstrated that superoxide ion can be generated electrochemically in room-temperature ionic-liquid solvents. In the absence of impurities, cyclic voltammetry showed that the super oxide ion is stable in these solvents. Similar superoxide ion chemistry has previously been demonstrated in volatile and environmentally suspect aprotic solvents such as dimethyl formamide and acetonitrile. However, ionic liquids are nonvolatile and should minimize the problems of secondary solvent waste. It is proposed that the resultant superoxide ion can be used to perform low temperature oxidation of wastes. Low-temperature oxidation of waste solvents can provide a much needed alternative to high-temperature waste incinerators, …


Deliquescence Of Nabh4 From Density Functional Theory And Experiments, Ping Li, Lin Yu, Michael Matthews, Wissam Saidi, J. Johnson Sep 2014

Deliquescence Of Nabh4 From Density Functional Theory And Experiments, Ping Li, Lin Yu, Michael Matthews, Wissam Saidi, J. Johnson

Michael A. Matthews

No abstract provided.


Kinetic Modeling Of Self-Hydrolysis Of Aqueous Nabh4 Solutions By Model-Based Isoconversional Method, Rajasree Retnamma, A. Novais, C. Rangel, Lin Yu, Michael Matthews Apr 2014

Kinetic Modeling Of Self-Hydrolysis Of Aqueous Nabh4 Solutions By Model-Based Isoconversional Method, Rajasree Retnamma, A. Novais, C. Rangel, Lin Yu, Michael Matthews

Michael A. Matthews

No abstract provided.


Determination Of The Lithium Ion Diffusion Coefficient In Graphite, Ping Yu, Branko Popov, James Ritter, Ralph White Dec 2012

Determination Of The Lithium Ion Diffusion Coefficient In Graphite, Ping Yu, Branko Popov, James Ritter, Ralph White

Dr Ping Yu

A complex impedance model for spherical particles was used to determine the lithium ion diffusion coefficient in graphite as a function of the state of charge (SOC) and temperature. The values obtained range from of 1.12 × 10–10 to 6.51 × 10–11 cm2/s at 25°C for 0 and 30% SOC, respectively, and for 0% SOC, the value at 55°C was 1.35 × 10–10 cm2/s. The conventional potentiostatic intermittent titration technique (PITT) and Warburg impedance approaches were also evaluated, and the advantages and disadvantages of these techniques were exposed