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Materials Science and Engineering

Chemical Engineering

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Full-Text Articles in Electromagnetics and Photonics

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.


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.


Giant Magnetostriction In Annealed Co1-XFeX Thin-Films, Dwight Hunter, Will Osborn, Ke Wang, Nataliya Kazantseva, Jason R. Hattrick-Simpers, Richard Suchoski, Ryota Takahashi, Marcus L. Young, Apurva Mehta, Leonid A. Bendersky, Same E. Lofland, Manfred Wuttig, Ichiro Takeuchi Mar 2015

Giant Magnetostriction In Annealed Co1-XFeX Thin-Films, Dwight Hunter, Will Osborn, Ke Wang, Nataliya Kazantseva, Jason R. Hattrick-Simpers, Richard Suchoski, Ryota Takahashi, Marcus L. Young, Apurva Mehta, Leonid A. Bendersky, Same E. Lofland, Manfred Wuttig, Ichiro Takeuchi

Jason R. Hattrick-Simpers

Chemical and structural heterogeneity and the resulting interaction of coexisting phases can lead to extraordinary behaviours in oxides, as observed in piezoelectric materials at morphotropic phase boundaries and relaxor ferroelectrics. However, such phenomena are rare in metallic alloys. Here we show that, by tuning the presence of structural heterogeneity in textured Co1−xFex thin films, effective magnetostriction λeff as large as 260 p.p.m. can be achieved at low-saturation field of ~10 mT. Assuming λ100 is the dominant component, this number translates to an upper limit of magnetostriction ofλ100≈5λeff >1,000 p.p.m. Microstructural analyses …


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.


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.


Exploration Of Artificial Multiferroic Thin-Film Heterostructures Using Composition Spreads, K.-S. Chang, M. A. Aronova, C.-L. Lin, M. Murakami, M.-H. Yu, Jason R. Hattrick-Simpers, O. O. Famodu, S. Y. Lee, R. Ramesh, M. Wuttig, I. Takeuchi, C. Gao, L. A. Bendersky Mar 2015

Exploration Of Artificial Multiferroic Thin-Film Heterostructures Using Composition Spreads, K.-S. Chang, M. A. Aronova, C.-L. Lin, M. Murakami, M.-H. Yu, Jason R. Hattrick-Simpers, O. O. Famodu, S. Y. Lee, R. Ramesh, M. Wuttig, I. Takeuchi, C. Gao, L. A. Bendersky

Jason R. Hattrick-Simpers

We have fabricated a series of composition spreads consisting of ferroelectric BaTiO3 and piezomagnetic CoFe2O4 layers of varying thicknesses modulated at nanometer level in order to explore artificial magnetoelectricthin-film heterostructures. Scanning microwavemicroscopy and scanning superconducting quantum interference device microscopy were used to map the dielectric and magnetic properties as a function of continuously changing average composition across the spreads, respectively. Compositions in the middle of the spreads were found to exhibit ferromagnetism while displaying a dielectric constant as high as ≈120.


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.