Identification: Tutorial EM10.2
Due to the technological limitation of flash memory, a significant number of new nonvolatile memories are now being proposed. The tutorial covers the fundamental physics behind the emerging nonvolatile memories. Resistive switching memory (ReRAM) technologies (based on non-phase change materials) and its application will be the focus of this tutorial. Presentations by two leading researchers will cover the fundamental background of devices.
Daniele Ielmini will describe the various modeling options at the physical and electronic level, concluding with an overview of how they can be used to realize neuromorphic devices and systems with a huge potential for adoption in many applications, such as accelerated machine learning and brain-inspired computation.
Identification: GS03
Developing classes of metal alloys, such as stabilized nano-crystalline alloys and multicomponent High Entropy Alloys (HEA), exhibit extraordinary mechanical and chemical properties. The structure of conventional alloys based on a single host element derive primarily from the chemical interactions of the components and the free energy as depicted in the equilibrium phase diagram. In nano-crystalline alloys or HEAs minimizing strain, minimizing surface energy, or increasing configurational entropy become primary factors controlling the crystal structure and microstructure often with surprising results. A multitude of alloys can be made using various combinations of elements known to be compatible, and many have already been created. However, for some alloys, chemical incompatibility leads to separation of elements in the liquid phase and makes production by conventional casting or splat quenching difficult[1]. We demonstrate a new method to form alloys from the liquid phase via irradiation of periodic thin films with a femtosecond laser.
We will present Transmission Electron Microscopy (TEM) of nano-crystalline NiW alloy, similar to those produced by electrodeposition[2], that was produced by irradiating a 23 nm thick film composed of 12 alternating layers of 1.4 nm W and 2.4 nm Ni. Femtosecond laser pulses are absorbed in the near surface heating the top 40 nm layer to extreme temperatures and pressures on the order of 6000 C and 50 GPa within a few picoseconds so the layer remains at solid density. The thermodynamic relaxation of the film passes into the “vapor dome” in the Temperature-Density phase diagram, a region of liquid-vapor coexistence where the bonding energy between atoms is low and the kinetic energy is very high. We propose under these extreme conditions Ni and W are allowed to mix thoroughly, then thermal transport into the substrate quenches the mixed layer within a few nanoseconds. It should be noted metals irradiated with a single ultrashort pulse do not resolidify nano-crystalline, but instead regrow epitaxially from the substrate. The thermal and mechanical relaxation of femtosecond laser irradiated multilayer films includes unique, extreme thermodynamic states and thereby provides a new route to synthesize stable nano-crystalline alloys or multicomponent HEAs from the liquid phase.
Identification: GS01
Identification: GS02
New solutions are needed to reduce the weight of the machines that move people and goods on land, sea and air. The potential for reducing weight using high-strength steels, aluminum, titanium and magnesium alloys is well established. Key is to achieve the weight reduction economically. This requires optimization of the material properties and processes together with robust design tools and joining technologies to enable multi-material structures. Lightweight Innovations for Tomorrow (LIFT) was established to accelerate the adoption of advanced metals and serves as the bridge between basic research and final product commercialization. Our industry partners in collaboration with an extensive network of universities and the national and federal laboratories are developing the next generation of advanced manufacturing processes. This talk will provide on overview of the challenges and describe how new materials and processes, coupled with Integrated Computational Materials Engineering, are advancing the technology.
Identification: GS-SWAI-1
Identification: GS05
Solid state electrolytes (SEs) in Li batteries are believed to be the ultimate solution to the electrode dissolution problems and safety hazards of liquid electrolyte (LE) systems. Sulfur based bulk type SE attracts great interest due to their relatively high ionic conductivities. Besides the bulk lithium ion conductivity, physical contact, structural evolution and redox reaction kinetics at SE and electrode interface during battery processes are other key factors that dictate the efficiency of battery cycling performances. The current challenge of studying the interfacial processes in operando in all solid battery systems is the difficulty of assembling an air-tight spectro-electrochemical cell with good electrical contact and optical accessibility to the interface of interest. In this work, a spectro-electrochemical cell is designed for an in operando Raman measurement at SE/Au interface during Li deposition and stripping processes. Three representative sulfur based SEs (β-Li3PS4, 70Li2S-30P2S5 glass ceramic (LPS-GS) and Li10GeP2S12 (LGPS)) were investigated. Spectroscopic data shows that, in general, partially reversible structural interconversion occurs among PS43-, P2S63-, P2S73- and other unidentified P-S anion species. Corresponding variations in cell impedance also supports these interfacial structural evolutions. Result reveals that in all solid Li battery systems, oxidation/reduction of Li+ occurs along with breaking and reformation of the Li+-Anion interactions, which are usually accompanied by some unexpected, partially irreversible structural evolution of the counter ions. The resulted byproducts are later accumulated at the electrode/electrolyte interfaces. This result not only help build the electrochemical fundamentals of the molecular details at solid-solid interface but also guide the choice of materials and interfaces in all solid Li battery systems.
Identification: GS06
Within the United Kingdom (UK) , it is proposed that nuclear waste will be disposed in a geological disposal facility, 200 m to 1 km underground1. This facility will incorporate an engineered barrier system that will be optimised to physically and chemically impede the transport of radionuclides to the biosphere. The facility will house a large volume of cemented Intermediate Level Waste (ILW), in addition to vitrified ILW. A significant volume of concrete will be used in its construction. Interaction of groundwater with the cementitious components of the facility (both the waste and construction materials) will lead to the presence of high pH conditions within a repository. The effect of cement leachates on vitrified wasteforms is not well understood.
We present results from a glass durability study using idealised cement leachates to develop our understanding of glass durability mechanisms in these complex repository like environments. Simulant ILW glasses relevant to the UK disposal program have been utilised. We also investigated a simulant UK high level waste glass (MW-25%) and the International Simple Glass2 (ISG), a 6 component borosilicate glass, with components that are common to most borosilicate nuclear glasses. Glass powders were exposed to idealised cement leachates of “intermediate” and “old” ages, approximately representative of GDF conditions at ~1000 and ~10,000 years of operation, according to the product consistency test B3. Analysis of the normalised mass loss and normalised leaching rate of these glasses as a function of cement leachate composition was achieved through analysis of solution concentrations. Simultaneously we present analysis of monolith sample alteration layers by SEM/EDX and GA-XRD. Collectively, these data support a mechanistic understanding of glass dissolution in the context of a complex geological disposal environment for vitrified UK waste
Identification: GS-SWAI-2
Scientific writing is an integral part of what a scientist does, and the value of a well-written paper should not be underestimated. Though it may seem overwhelming, the writing process can help to guide experiments and enable a deeper understanding of experimental results.
Although writing styles and processes can differ tremendously between authors, there are a host of characteristics that are common to effective writing strategies and well-written scientific papers. In this session we will discuss the elements of well-written papers; strategies by which to efficiently translate ideas to experiments to high-quality publications; how to prepare effective figures; and how to respond to reviewer comments to get your paper accepted.
By the end of this session, you will come to realize that scientific writing can be easy, enjoyable, efficient, and rewarding.
Identification: GS08
Identification: GS-SWAI-3
Different funding agencies all have their own unique missions and selection criteria for choosing which proposals to fund. This can make crafting proposals directed toward these organizations quite a difficult task.
In this workshop, Gnade will discuss what criteria different funding agencies look for in successful proposals. The discussion will cover how to evaluate funding opportunities in order to develop a strategy on where to submit proposals and examples of successful proposals.