Thank you!

The 2019 MRS Fall Meeting & Exhibit came to a successful conclusion on Friday, December 6. Our congratulations go to Meeting Chairs Bryan D. Huey, Stéphanie P. Lacour, Conal E. Murray, Jeffrey B. Neaton, and Iris Visoly-Fisher for putting together an excellent technical program along with various special events. MRS would also like to thank all the Symposium Organizers, Session Chairs, and Symposium Assistants for their part in the success of this meeting. A thank you goes to the Exhibitors, Symposium Support, and to the sponsors of the special events and activities.

Contributors to news on the 2019 MRS Fall Meeting & Exhibit include Meeting Scene reporters Tomojit Chowdhury (@TomojitC),Tianyu Liu (@Tianyuliu_Chem), Judy Meiksin (@Judy_Meiksin), Don Monroe, Jahlani Odujole, Alana F. Ogata (@OgataAlana), and Arthur L. Robinson; Bloggers Nabasindhu Das, Abhishek Dubey (@adubeyphy), Araceli Hernández Granados (@AraceliHG02), and Anja Sutoriu; and photographers Stephanie Gabborin and Heather Shick; with newsletter production by Karen Colson, and newsletter design by Erin Hasinger.

Thank you to MRS Meeting Scene sponsors SPI SuppliesGoodfellow CorporationLake Shore Cryotronics, Inc.American ElementsWiley; Rigaku; and American Physical Society.      

Thank you for subscribing to the MRS Meeting Scene newsletters from the 2019 MRS Fall Meeting & Exhibit. We hope you enjoyed reading them and continue your subscription as we launch into the 2020 MRS Spring Meeting & Exhibit - the conversation already started at #s20mrs! We welcome your comments and feedback.


MRS Frontiers Reception—Building Communities

Thursday evening activities opened with a lot of fun and creativity. Beginning with PowerPoint Karaoke, risk-taking participants explained the science behind a one-slide PPT which they saw for the first time and had only 30-seconds to prepare! Typically, the topic was not in their field of study. This exercise demonstrates the importance of clearly communicating research in pictures via PPT as well as poster presentations. It also points toward the places where materials advancements in one specialized area informs another area of study. Taking an example from the scientific talks given during the week, when Yuan Yang of Columbia University reported on biological imaging of chemical bonds by using the stimulated Raman scattering (SRS) microscope, Yang also pointed out the advantages of SRS microscopy for imaging lithium ion transport during dendrite formation in lithium ion batteries.    

Frontiers_800x800

After PPT Karaoke, the MRS volunteers involved in introducing new topical areas of study to the MRS membership engaged the Karaoke crowd as well as many other Meeting attendees to brainstorm new directions at the frontiers of materials research. The topical areas included materials for sustainability and artificial intelligence along with biomaterials, quantum materials, and responsive & adaptive materials. During this reception (accompanied with food and beverage), materials researchers came up with questions such as whether self-healing materials can be accomplished at the quantum level. They considered combined specialties such as external stimuli responsive systems for drug delivery. In the biomaterials area, scientists reached for interaction with nature such as naturopathic drug development; interaction between cells, tissues, and sound waves; and a biomimetic system that can fool the real biological systems.

As the news editor for MRS Bulletin, I’ll be looking for these studies coming to fruition!

-Judy Meiksin  


Best Poster Award Winners – Thursday

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Alexander Hernandez Oendra, ETH Zurich

EN09.13.08 Template Stripping of Perovskite Thin Films for Dry Interfacing and Surface Structuring

 

Rachel Smith, Massachusetts Institute of Technology

SB01.12.19 Manufacturing Biohybrid Textiles through a Robust Fiber Based Cell-Free Expression System

 

Lazaro Padilha, Universidade Estadual de Campinas

EN10.16.07 Multi-Exciton Interactions and Size—An Interplay for Efficient Two-Photon Induced Gain in Perovskite Quantum Dots

 

 

 


The Von Hippel Award Presentation

Von Hippel_800x800Jerry D. Tersoff, IBM T.J. Watson Research Center 

Simple Models for Complex Behavior in Nanowire Growth

Written by Arthur L. Robinson

In his Von Hippel Award presentation Wednesday evening, Jerry Tersoff of the IBM T.J. Watson Research Center observed from experience that problems arising from experimental puzzles were able to bring out the best of him as a theorist. For example, a theme of his research has been to find simple models that capture some element of some very complex experimental situation. To illustrate this approach, Tersoff turned to growth of semiconductor nanowires, which provide unique opportunities for studying crystal growth. Their small diameter guarantees single-crystal growth, and they can be grown in a transmission electron microscope (TEM). Because nanowires are so thin, they are electron transparent, and researchers can capture the entire growth region in a single image, recording growth in situ under UHV conditions, in effect a laboratory for studying fundamental issues of crystal growth. A number of remarkable phenomena have been discovered in this way, some of which are specific to nanowires. In his presentation, Tersoff described a few of these intriguing observations and demonstrated how even very simple models can give useful insight into the behavior and in the process deepening our understanding of nanoscale materials.

Nanowires actually have a long history, going back to the 1960s, when researchers were able to grow vertical silicon whiskers on a silicon substrate by depositing a gold layer on the substrate and heating. The resulting gold-silicon liquid acts as a catalyst for silicon growth when exposed to a silane (S2H6) source. Today wires with 10- to 100-nm diameters can be readily grown in this way (but without gold, which would be detrimental to devices) for use in photovoltaics and transistors based on self-assembled semiconductor nanostructures with dimensions smaller than lithography can handle.

One benefit of studying with the TEM emerged right away. The conventional view had been that the ideal wires were long and straight, but reality intervened with a closer look by experimentalists at the walls, which actually had a sawtooth edge. This finding drew Tersoff into the discussion, and the deal was sealed when around 2010 researchers showed images in which the wires could sometimes grow in a temperature-controlled zigzag path and were not always normal to the substrate surface. Tersoff asked what kind of model could capture such “weird” behaviors and ruled out atomistic simulations as too unwieldy. What he and a colleague came up with was what he called a two-dimensional faceted continuum model based on three “elementary processes”: facet growth, droplet statics, and introduction of new facets.

Von Hippel 2_800x800Unpacking the three elements, Tersoff explained that facet growth was by means of liquid phase epitaxy from supersaturated liquid. Droplet statics was about droplet stability as the droplet size changed. The really new element, facet addition, included all infinitesimal process that add only one edge with a parameter characterizing edge energy as a barrier to growing new facets. Tersoff said that the spirit of their model resembles that of a 1990s model for faceted crystal growth but with addition of the droplets. Subsequent extensive simulations suggested that these three elements are sufficient to explain many of the observed observations.

Applying the model to growth of the original vertical silicon wire with sawtoothed edges seemed too complicated for the first attempt, so Tersoff’s group first turned to a longer and more uniform configuration that grows at an angle relative to the substrate surface but is not sawtoothed. The calculation is an iterative one with checks for stability of droplets and facets at each time step. The simulation reproduced the nanowire, and it was even possible to account for changing parameters like temperature that, for example, caused the gold to diffuse out of the droplet, introducing a taper in the wire by means of jogs to account for the changing diameter. They also found that changing the edge-energy parameter could change the growth mode, with behaviors like crawling, resulting in lateral growth, and kinking. Returning to the vertical wire configuration, the researchers found that they could reproduce the sawtooth, which was due to a geometrical frustration when there is no plane normal to the growth plane to serve as the wall. By introducing three new facets with a slightly higher edge energy, the growth was stabilized without eliminating the geometrical frustration but generated the sawtooth. The model also correctly predicted the change in the sawtooth period with nanowire diameter. Finally, experiments verified the change in growth mode from vertical with sawtooth to tilted without sawtooth by introducing oxygen into the growth chamber to vary the energy parameter.

Summing up his presentation, Tersoff concluded that he and his colleagues had identified three elementary processes in nanowire growth and captured these three elements in a dynamical facet-growth model that enabled direct simulations of complex growth, including kinking and crawling behaviors and sawtooth growth. They also used the model to discover new oscillatory growth modes, and pave the way for detailed comparison of experiment and simulation to advance the understanding of nanowire growth.

The Materials Research Society’s highest honor, the Von Hippel Award, is conferred annually to an individual in recognition of the recipient’s outstanding contribution to interdisciplinary research on materials.

 


Best Poster Award Winners – Wednesday

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Samuel White, Vanderbilt University

FF01.16.09 Large, Low-Aspect Ratio Vanadium Dioxide Single Crystals as Actively Reconfigurable Substrates for 2D Materials

 

Armi Tiihonen, Massachusetts Institute of Technology

MT02.09.01 Machine Learning for Revealing Aging Mechanisms of Perovskite Solar Cells

 

Kristopher Williams, Massachusetts Institute of Technology

EN09.10.18 The Unexpected Role of Composition in Perovskite Diffusion

 

Hakan Arslan, University of Texas at Arlington

SB04.08.13 3D Printing of Anisotropic Hydrogels with Bioinspired Motion

 

Luke MacQueen, Harvard University

SB02.11.17, A Tissue-Engineered Scale Model of the Heart Ventricle


2019 Fall Meeting: Science in Video Competition

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Photo Credits:

Front Row (L-R): Taryn Fuhrman (MilliporeSigma), Second Place: Naila Al for Joy (Hsin-Yun) Chao, People’s Choice: Anshika Goel, Honorable Mention: Luizetta Navrazhnykh Elliott.

Back Row (L-R): Stephen Aldersley (Goodfellow), Babak Anasori (IUPUI, SciVid organizer), First Place: Bilen Akuzum, Third Place: Shefford Baker for Karl Ashkar.

 

The Competition for the Science in Video has now ended and here are the Winners:

 

First Place

Title: Go with the Flow: Electrodes of the Future

Authors:  Bilen Akuzum, Simge Uzun, Yury Gogotsi, E. Caglan Kumbur

From Drexel University

 

Second Place

Title: ConTEMplating Atomic Resolution

Authors:  Joy (Hsin-Yun) Chao, Zoey Warecki

From University of Maryland - College Park, National Institute of Standards and Technology

 

Third Place

Title: Lenses of the Future

Authors:  Karl Ashkar, Caleb Harden

From Cornell University

 

People´s Choice

Title: Lithium-ion batteries (Coin cells) in making.

Authors: Anshika Goel and Marc F. Hidalgo, Chetan S. Pawar Sr.

From Binghamton University (M.S. Whittingham group), Adobe Systems

 

Honorable Mention

Title: Tiny medical devices with shape memory polymers

Authors: Luizetta Navrazhnykh Elliott, Erika Salzman, Julia R. Greer, Rasa Pictures

From California Institute of Technology

 

2019 SciVid Competition sponsored by Goodfellow, Millipore Sigma, the Materials Research Society Foundation and A. J. Drexel Nanomaterials Institute