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Reactive sputter deposition of piezoelectric Sc0.12Al0.88N for contour mode resonators

Journal of Vacuum Science and Technology B: Nanotechnology and Microelectronics

Henry, Michael D.; Young, Travis R.; Douglas, Erica A.; Griffin, Benjamin G.

Substitution of Al by Sc has been predicted and demonstrated to improve the piezoelectric response in AlN for commercial market applications in radio frequency filter technologies. Although cosputtering with multiple targets have achieved Sc incorporation in excess of 40%, industrial processes requiring stable single target sputtering are currently limited. A major concern with sputter deposition of ScAl is the control over the presence of non-c-axis oriented crystal growth, referred to as inclusions here, while simultaneously controlling film stress for suspended microelectromechanical systems (MEMS) structures. This work describes 12.5% ScAl single target reactive sputter deposition process and establishes a direct relationship between the inclusion occurrences and compressive film stress allowing for the suppression of the c-axis instability on silicon (100) and Ti/TiN/AlCu seeding layers. An initial high film stress, for suppressing inclusions, is then balanced with a lower film stress deposition to control total film stress to prevent Euler buckling of suspended MEMS devices. Contour mode resonators fabricated using these films demonstrate effective coupling coefficients up to 2.7% with figures of merit of 42. This work provides a method to establish inclusion free films in ScAlN piezoelectric films for good quality factor devices.

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TYPE Journal Article YEAR 2018
DOIOSTIScopus

Pressurized Slot Testing to Determine Thermo-Mechanical Properties of Lithophysal Tuff at Yucca Mountain Nevada

George, James T.; Sobolik, Steven R.; Lee, Moo Y.; Park, Byoung P.; Costin, Laurence

The study described in this report involves heated and unheated pressurized slot testing to determine thermo-mechanical properties of the Tptpll (Tertiary, Paintbrush, Topopah Spring Tuff Formation, crystal poor, lower lithophysal) and Tptpul (upper lithophysal) lithostratigraphic units at Yucca Mountain, Nevada. A large volume fraction of the proposed repository at Yucca Mountain may reside in the Tptpll lithostratigraphic unit. This unit is characterized by voids, or lithophysae, which range in size from centimeters to meters, making a field program an effective method of measuring bulk thermal-mechanical rock properties (thermal expansion, rock mass modulus, compressive strength, time-dependent deformation) over a range of temperature and rock conditions. The field tests outlined in this report provide data for the determination of thermo-mechanical properties of this unit. Rock-mass response data collected during this field test will reduce the uncertainty in key thermal-mechanical modeling parameters (rock-mass modulus, strength and thermal expansion) for the Tptpll lithostratigraphic unit, and provide a basis for understanding thermal-mechanical behavior of this unit. The measurements will be used to evaluate numerical models of the thermal-mechanical response of the repository. These numerical models are then used to predict pre- and post-closure repository response. ACKNOWLEDGEMENTS The authors would like to thank David Bronowski, Ronnie Taylor, Ray E. Finley, Cliff Howard, Michael Schuhen (all SNL) and Fred Homuth (LANL) for their work in the planning and implementation of the tests described in this report. This is a reprint of SAND2004-2703, which was originally printed in July 2004. At that time, it was printed for a restricted audience. It has now been approved for unlimited release.

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TYPE SAND Report YEAR 2018
DOIOSTI

Electrical cable utilization for wave energy converters

Journal of Ocean Engineering and Marine Energy

Bull, Diana L.; Baca, Michael J.; Schenkman, Benjamin L.

This paper investigates the suitability of sizing the electrical export cable based on the rating of the contributing WECs within a farm. These investigations have produced a new methodology to evaluate the probabilities associated with peak power values on an annual basis. It has been shown that the peaks in pneumatic power production will follow an exponential probability function for a linear model. A methodology to combine all the individual probability functions into an annual view has been demonstrated on pneumatic power production by a Backward Bent Duct Buoy (BBDB). These investigations have also resulted in a highly simplified and perfunctory model of installed cable cost as a function of voltage and conductor cross-section. This work solidifies the need to determine electrical export cable rating based on expected energy delivery as opposed to device rating as small decreases in energy delivery can result in cost savings.

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TYPE Journal Article YEAR 2018
DOIOSTIScopus

Changing the Engineering Design & Qualification Paradigm in Component Design & Manufacturing (Born Qualified)

Roach, R.A.; Bishop, Joseph E.; Jared, Bradley H.; Keicher, David M.; Cook, Adam W.; Whetten, Shaun R.; Forrest, Eric C.; Stanford, Joshua S.; Boyce, Brad B.; Johnson, Kyle J.; Rodgers, Theron R.; Ford, Kurtis R.; Martinez, Mario J.; Moser, Daniel M.; van Bloemen Waanders, Bart G.; Chandross, M.; Abdeljawad, Fadi F.; Allen, Kyle M.; Stender, Michael S.; Beghini, Lauren L.; Swiler, Laura P.; Lester, Brian T.; Argibay, Nicolas A.; Brown-Shaklee, Harlan J.; Kustas, Andrew K.; Sugar, Joshua D.; Kammler, Daniel K.; Wilson, Mark A.

Abstract not provided.

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TYPE Presentation YEAR 2018
OSTIOSTI

Morgan Bradley_MGMT497_Final Portfolio_v2

Shafto, Morgan L.

I work as a Year-Round Business Intern at Sandia National Laboratories. Sandia was founded during WWII under the name of Z Division as the manufacturers and assembly hands of nuclear weapons for Los Alamos National Laboratories. In the year 1948, the name Z Division was changed to Sandia National Laboratories. Sandia is a government-owned, contractoroperated facility. This means that while Sandia's work is largely government-funded Sandia is operated by a 3rd party contractor. Over the years, Sandia has been managed by different organizations, but as of May l', 2017, the current management company became the National Technology and Engineering Solutions of Sandia (NTESS) LLC.

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TYPE Other Report YEAR 2018
DOIOSTI

Exemplar for simulation challenges: Large-deformation micromechanics of Sylgard 184/glass microballoon syntactic foams

Brown, Judith A.; Long, Kevin N.

Sylgard® 184/Glass Microballoon (GMB) potting material is currently used in many NW systems. Analysts need a macroscale constitutive model that can predict material behavior under complex loading and damage evolution. To address this need, ongoing modeling and experimental efforts have focused on study of damage evolution in these materials. Micromechanical finite element simulations that resolve individual GMB and matrix components promote discovery and better understanding of the material behavior. With these simulations, we can study the role of the GMB volume fraction, time-dependent damage, behavior under confined vs. unconfined compression, and the effects of partial damage. These simulations are challenging and push the boundaries of capability even with the high performance computing tools available at Sandia. We summarize the major challenges and the current state of this modeling effort, as an exemplar of micromechanical modeling needs that can motivate advances in future computing efforts.

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TYPE Other Report YEAR 2018
DOIOSTI

A Wolter Imager on the Z Machine to Diagnose Warm X-ray Sources

Ampleford, David A.; Fein, Jeffrey R.; J K Vogel, B.K.; Kozioziemski, B.J.; Walton, C.C.; Wu, Ming W.; Ball, Christopher R.; A Ames, J.A.; Bell, P.; Bourdon, Christopher B.; D Bradley, R.B.; Dunham, Gregory S.; Gard, Paul D.; Johnson, Drew J.; Kilaru, K.; Lake, Patrick W.; Maurer, A.; Nielsen-Weber, Linda B.; Pickworth, L.A.; M Pivovaroff, S.R.; Ramsey, B.; Roberts, O.J.; Sullivan, Michael A.; Rochau, G.A.

Abstract not provided.

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TYPE Presentation YEAR 2018
OSTIOSTI
Results 28201–28400 of 96,771
Results 28201–28400 of 96,771