Role of scaffold network in controlling strain and functionalities of nanocomposite films

Strain is a novel approach to manipulating functionalities in correlated complex oxides. However, significant epitaxial strain can only be achieved in ultrathin layers. We show that, under direct lattice matching framework, large and uniform vertical strain up to 2% can be achieved to significantly modify the magnetic anisotropy, magnetism, and magnetotransport properties in heteroepitaxial nanoscaffold films, over a few hundred nanometers in thickness. Comprehensive designing principles of large vertical strain have been proposed. Phase-field simulations not only reveal the strain distribution but also suggest that the ultimate strain is related to the vertical interfacial area and interfacial dislocation density. By changing the nanoscaffold density and dimension, the strain and the magnetic properties can be tuned. The established correlation among the vertical interface—strain—properties in nanoscaffold films can consequently be used to tune other functionalities in a broad range of complex oxide films far beyond critical thickness.

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Low Permittivity SiO2/Void Nanocomposite Films

MRS Proceedings ◽

10.1557/proc-72-27 ◽

1986 ◽

Vol 72 ◽

Cited By ~ 2

Author(s):

Amitabh Das ◽

R. Messier ◽

T. R. Gururaja ◽

L. E. Cross

Keyword(s):

Thin Film ◽

High Speed ◽

Columnar Structure ◽

Nanocomposite Films ◽

Strip Line ◽

Gel Layer ◽

Novel Approach ◽

Sputter Deposited ◽

Low Permittivity ◽

Potential Use

AbstractA novel approach for preparing porous SiO2 thin films by sputter deposi-tion is being developed. The porosity is introduced to reduce the dielectric permittivity of the film to less than 3 for potential use in packaging high speed VLSIs. In the first approach, amorphous silicon is initially deposited to produce a columnar structure with a thickness of 25μm, followed by etching and thermal oxidation to result in closely spaced SiO2 pillars. Capping the structure by a thin film (0.1μm), silica gel layer provides the support for strip line traces. In the second approach, porous SiO2 films are prepared by reactive sputtering. The dielectric properties of the sputter deposited SiO2 films are presented.

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Lattice matching periodic interfacial dislocation network in surfactant-mediated growth of Ge on Si(111)

phys stat sol (a) ◽

10.1002/pssa.2211460129 ◽

1994 ◽

Vol 146 (1) ◽

pp. 337-352 ◽

Cited By ~ 14

Author(s):

M. Horn-von Hoegen ◽

M. Henzler

Keyword(s):

Dislocation Network ◽

Interfacial Dislocation ◽

Lattice Matching

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Structural and chemical analysis of Pd-Ge ohmic contacts to epitaxially lifted-off GaAs

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100171948 ◽

1994 ◽

Vol 52 ◽

pp. 842-843

Author(s):

R. Rajesh ◽

J. Liu ◽

H. Fathollahnejad ◽

R. W. Carpenter ◽

G. N. Maracas

Keyword(s):

Low Temperature ◽

Ohmic Contacts ◽

Lattice Matching ◽

Low Resistance ◽

Gaas On Si ◽

Low Temperature Annealing ◽

Gaas Devices ◽

Direct Lattice ◽

Lift Off ◽

Matching Criteria

For the past decade, there has been considerable focus on low resistance Pd-Ge ohmic contacts to GaAs. One approach toward achieving thermodynamically stable ohmic contacts is to consider solid-phasereactions for contacts, rather than the liquid phase interactions that occur upon ohmic alloying of Au-Ge-based systems. The two classifications to this approach are: low temperature annealing (<500°C), mainly using Pd, and high temperature annealing (<500°C), mainly using In. The low temperature annealing class is more compatible with existing GaAs technology, hence the attention to Pd-based systems, particularly Pd-Ge. There has also been tremendous interest in hybrid GaAs-on-Si technology. As an alternative to direct lattice-mismatched growth of GaAs on Si, the epitaxial lift-off (ELO) technique has been used, wherein GaAs devices grown on GaAs substrates can be removed and bonded to any substrate regardless of orientation and/or lattice matching criteria. This process yields high quality dislocation-free GaAs-based devices for hybrid applications.In this study, we demonstrate a low resistance non-alloyed Pd-Ge ohmic contact to epitaxialiy lifted-off n-type GaAs.

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Nonporous, Strong, Stretchable, and Transparent Electrospun Aromatic Polyurea Nanocomposites as Potential Anticorrosion Coating Films

Nanomaterials ◽

10.3390/nano11112998 ◽

2021 ◽

Vol 11 (11) ◽

pp. 2998

Author(s):

Sheik Ambarine Banon Auckloo ◽

Khanisya Palaniandy ◽

Yew Mun Hung ◽

Giuseppe Lazzara ◽

Siang-Piao Chai ◽

...

Keyword(s):

Tensile Strength ◽

Polymer Coatings ◽

Nanocomposite Films ◽

Coating Films ◽

Water Contact ◽

Degradation Temperature ◽

Novel Approach ◽

Multi Walled Carbon Nanotubes ◽

Heat Exchanges ◽

Walled Carbon Nanotubes

This study, for the first time, focused on the fabrication of nonporous polyurea thin films (~200 microns) using the electrospinning method as a novel approach for coating applications. Multi-walled carbon nanotubes (MWCNTs) and hydrophilic-fumed nanosilica (HFNS) were added separately into electrospun polyurea films as nano-reinforcing fillers for the enhancement of properties. Neat polyurea films demonstrated a tensile strength of 14 MPa with an elongation of 360%. At a loading of 0.2% of MWCNTs, the highest tensile strength of 21 MPa and elongation of 402% were obtained, while the water contact angle remained almost unchanged (89°). Surface morphology analysis indicated that the production of polyurea fibers during electrospinning bonded together upon curing, leading to a nonporous film. Neat polyurea exhibited high thermal resistance with a degradation temperature of 380 °C. Upon reinforcement with 0.2% of MWCNTs and 0.4% of HFNS, it increased by ~7 °C. The storage modulus increased by 42 MPa with the addition of 0.2% of MWCNTs, implying a superior viscoelasticity of polyurea nanocomposite films. The results were benchmarked with anti-corrosive polymer coatings from the literature, revealing that the production of nonporous polyurea coatings with robust strength, elasticity, and thermal properties was achieved. Electrospun polyurea coatings are promising candidates as flexible anti-corrosive coatings for heat exchanges and electrical wires.

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Novel approach for modeling kinetic interface-sensitive (KIS) tracers with respect to time-dependent interfacial area change for the optimization of supercritical carbon dioxide injection into deep saline aquifers

International Journal of Greenhouse Gas Control ◽

10.1016/j.ijggc.2014.11.020 ◽

2015 ◽

Vol 33 ◽

pp. 145-153 ◽

Cited By ~ 8

Author(s):

Alexandru Bogdan Tatomir ◽

Mario Schaffer ◽

Alexander Kissinger ◽

Johannes Hommel ◽

Philipp Nuske ◽

...

Keyword(s):

Carbon Dioxide ◽

Supercritical Carbon Dioxide ◽

Interfacial Area ◽

Time Dependent ◽

Saline Aquifers ◽

Carbon Dioxide Injection ◽

Area Change ◽

Novel Approach ◽

Deep Saline Aquifers ◽

Supercritical Carbon

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Electron microscopic characterization of diamond thin films and substrates for diamond heteroepitaxial growth

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100154937 ◽

1989 ◽

Vol 47 ◽

pp. 592-593

Author(s):

J.B. Posthill ◽

R.P. Burns ◽

R.A. Rudder ◽

Y.H. Lee ◽

R.J. Markunas ◽

...

Keyword(s):

Thin Films ◽

Wide Band ◽

Deposition Process ◽

Heteroepitaxial Growth ◽

Electron Microscopic ◽

Wide Band Gap ◽

Lattice Matching ◽

Different Types ◽

Diamond Thin Films

Because of diamond’s wide band gap, high thermal conductivity, high breakdown voltage and high radiation resistance, there is a growing interest in developing diamond-based devices for several new and demanding electronic applications. In developing this technology, there are several new challenges to be overcome. Much of our effort has been directed at developing a diamond deposition process that will permit controlled, epitaxial growth. Also, because of cost and size considerations, it is mandatory that a non-native substrate be developed for heteroepitaxial nucleation and growth of diamond thin films. To this end, we are currently investigating the use of Ni single crystals on which different types of epitaxial metals are grown by molecular beam epitaxy (MBE) for lattice matching to diamond as well as surface chemistry modification. This contribution reports briefly on our microscopic observations that are integral to these endeavors.

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Copper-dependent ATP7B up-regulation drives the resistance of TMEM16A-overexpressing head-and-neck cancer models to platinum toxicity

Biochemical Journal ◽

10.1042/bcj20190591 ◽

2019 ◽

Vol 476 (24) ◽

pp. 3705-3719 ◽

Cited By ~ 2

Author(s):

Avani Vyas ◽

Umamaheswar Duvvuri ◽

Kirill Kiselyov

Keyword(s):

Oxidative Stress ◽

Head And Neck ◽

Transcriptional Activation ◽

Platinum Resistance ◽

Mrna Levels ◽

Strong Positive Correlation ◽

Platinum Compounds ◽

Copper Chelation ◽

Novel Approach ◽

Cancer Models

Platinum-containing drugs such as cisplatin and carboplatin are routinely used for the treatment of many solid tumors including squamous cell carcinoma of the head and neck (SCCHN). However, SCCHN resistance to platinum compounds is well documented. The resistance to platinum has been linked to the activity of divalent transporter ATP7B, which pumps platinum from the cytoplasm into lysosomes, decreasing its concentration in the cytoplasm. Several cancer models show increased expression of ATP7B; however, the reason for such an increase is not known. Here we show a strong positive correlation between mRNA levels of TMEM16A and ATP7B in human SCCHN tumors. TMEM16A overexpression and depletion in SCCHN cell lines caused parallel changes in the ATP7B mRNA levels. The ATP7B increase in TMEM16A-overexpressing cells was reversed by suppression of NADPH oxidase 2 (NOX2), by the antioxidant N-Acetyl-Cysteine (NAC) and by copper chelation using cuprizone and bathocuproine sulphonate (BCS). Pretreatment with either chelator significantly increased cisplatin's sensitivity, particularly in the context of TMEM16A overexpression. We propose that increased oxidative stress in TMEM16A-overexpressing cells liberates the chelated copper in the cytoplasm, leading to the transcriptional activation of ATP7B expression. This, in turn, decreases the efficacy of platinum compounds by promoting their vesicular sequestration. We think that such a new explanation of the mechanism of SCCHN tumors’ platinum resistance identifies novel approach to treating these tumors.

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Collecting Words: A Clinical Example of a Morphology-Focused Orthographic Intervention

Language Speech and Hearing Services in Schools ◽

10.1044/2020_lshss-19-00050 ◽

2020 ◽

Vol 51 (3) ◽

pp. 544-560 ◽

Cited By ~ 3

Author(s):

Kimberly A. Murphy ◽

Emily A. Diehm

Keyword(s):

Written Language ◽

Morphological Knowledge ◽

English Orthography ◽

Word Level ◽

Novel Approach ◽

Language Pathology ◽

The One ◽

Critical Intervention ◽

Reading And Spelling ◽

Reading And Spelling Difficulties

Purpose Morphological interventions promote gains in morphological knowledge and in other oral and written language skills (e.g., phonological awareness, vocabulary, reading, and spelling), yet we have a limited understanding of critical intervention features. In this clinical focus article, we describe a relatively novel approach to teaching morphology that considers its role as the key organizing principle of English orthography. We also present a clinical example of such an intervention delivered during a summer camp at a university speech and hearing clinic. Method Graduate speech-language pathology students provided a 6-week morphology-focused orthographic intervention to children in first through fourth grade ( n = 10) who demonstrated word-level reading and spelling difficulties. The intervention focused children's attention on morphological families, teaching how morphology is interrelated with phonology and etymology in English orthography. Results Comparing pre- and posttest scores, children demonstrated improvement in reading and/or spelling abilities, with the largest gains observed in spelling affixes within polymorphemic words. Children and their caregivers reacted positively to the intervention. Therefore, data from the camp offer preliminary support for teaching morphology within the context of written words, and the intervention appears to be a feasible approach for simultaneously increasing morphological knowledge, reading, and spelling. Conclusion Children with word-level reading and spelling difficulties may benefit from a morphology-focused orthographic intervention, such as the one described here. Research on the approach is warranted, and clinicians are encouraged to explore its possible effectiveness in their practice. Supplemental Material https://doi.org/10.23641/asha.12290687

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