MRS Bulletin - Cover Gallery
Volume 49 - Issue 9
Volume 49 - Issue 8
Volume 49 - Issue 7
Volume 49 - Issue 6
Volume 49 - Issue 5
Volume 49 - Issue 4
Volume 49 - Issue 3
Volume 49 - Issue 2
Volume 49 - Issue 1
Volume 48 - Issue 12
Volume 48 - Issue 11
Volume 48 - Issue 10
Volume 48 - Issue 9
Volume 48 - Issue 8
Volume 48 - Issue 7
Volume 49 - Issue 6
Volume 48 - Issue 5
Volume 48 - Issue 4
Volume 48 - Issue 3
Volume 48 - Issue 2
Volume 48 - Issue 1
Volume 47 - Issue 12
Volume 47 - Issue 11
Volume 47 - Issue 10
Volume 47 - Issue 9
Volume 47 - Issue 8
Volume 47 - Issue 7
Volume 47 - Issue 6
Volume 47 - Issue 5
Volume 47 - Issue 4
Volume 47 - Issue 3
Volume 47 - Issue 2
Volume 47 - Issue 1
Volume 46 - Issue 12
Volume 46 - Issue 11
Volume 46 - Issue 10
Volume 46 - Issue 9
Volume 46 - Issue 8
Volume 46 - Issue 7
Volume 46 - Issue 6
Volume 46 - Issue 5
Volume 46 - Issue 4
Volume 46 - Issue 3
Volume 46 - Issue 2
Volume 46 - Issue 1
Volume 45 Issue 12
Processing Metallic Materials Far from Equilibrium
Volume 45 - Issue 11 - November 2020
Recent rapid advances in modeling and real-time experiments with solidifi cation of metals and alloys have yielded a wealth of new and quantitative information, expanding our understanding of the liquid-to-solid phase transition. This is critical to understand the formation of solid phases and their shapes and patterns from the disordered liquid environment. This issue of MRS Bulletin highlights developments in the fi eld, including solidification at extreme rates, as well as the state of the art in computational and experimental techniques. The cover shows dynamic transmission electron microscope images of an Al-4Cu solid-liquid interface during the transition from incubation to growth with corresponding phase-field simulations, showing the interface morphology and grain structure. The background shows directional solidifi cation of (upper) Al-Cu and (lower) Al-Si alloys observed through synchrotron x-ray images. Credit for image in foreground: J.T. McKeown, T. Pinomaa, J.M.K. Wiezorek, N. Provatas, A. Laukkanen, and T. Suhonen. Background: A.J. Clarke, S.D. Imhoff, P.J. Gibbs, J.W. Gibbs, K. Fezzaa, and D. Tourret. See the technical theme that begins on p. 906.
Functional Materials and Devices by Self-Assembly
Volume 45 - Issue 10 - October 2020
Self-assembly allows for the development of new paradigms for chemistry and materials science, where various, typically nanometer-sized, objects with precisely engineered sizes, shapes, compositions, and concomitant properties serve as “meta-atoms” or superatomic building blocks for hierarchically assembled materials and devices. The current state of the field reveals that self-assembly is making significant strides toward applications in nanoelectronics, photonics, energy storage, chemical separations, and as a path to form complex structures. The cover shows singlecrystal nanoparticle superlattices assembled via DNA hybridization. The cover image relates to US Department of Navy Award No. N00014-19-1-2213 issued by the Office of Naval Research. The United States Government has a royalty-free license throughout the world to the image. See the technical theme that begins on p. 799.
Liquid Phase Electron Microscopy
Volume 45 - Issue 9 - September 2020
Liquid phase or liquid cell transmission electron microscopy (TEM) is a powerful and emergent platform for nanoscale imaging and characterization of physical, chemical, and biological processes of materials in liquids. It can be used to explore nanoscale details of solution processes directly. Details of the development and applications of liquid cell TEM are discussed in this issue of MRS Bulletin. The cover shows a stylized representation of liquid phase TEM. The smaller image in the top left is a microfabricated fl ow liquid cell that sandwiches a thin layer of solution containing either a precursor solution or nanoparticles between two ultrathin SiNx membrane windows that are separated by a spacer. On the bottom left is a static graphene liquid cell that sandwiches nanodroplet pockets of precursor solution between two graphene layers. See the technical theme that begins on p. 704.
Organic Semiconductors for Brain-Inspired Computing
Volume 45 - Issue 8 - August 2020
The next generation of neuromorphic computing must not just simulate but rather more effectively emulate neural functions. This has led to a surge in research activity to discover and revisit materials systems that effi ciently implement various neural functions. This issue of MRS Bulletin describes the multiple avenues by which neural processes have been pursued in the past decades, and future opportunities and challenges that lie ahead for the fi eld of neuromorphic devices using organic materials. The cover features a schematic of an afferent nerve, where applied pressure initiates action potentials in nature. The artifi cial afferent nerve is comprised of pressure sensors, a ring oscillator, and a three-terminal neuromorphic device (synaptic transistor). Adapted with permission from Science (AAAS). See the technical theme that begins on p. 619.
Nanomaterials for Electrochemical Water Splitting
Volume 45 - Issue 7 - July 2020
Water-splitting electrolysis using an electrocatalyst and a renewable power source is a promising energy-conversion technology, especially when combined with energy stored in the form of hydrogen that has the benefi t of also being environmentally friendly. The electrocatalyst can be rationally designed using nanomaterials spanning from transition-metalbased oxides and their derivatives, organic polymer nanomaterials, to inorganic–organic nanocomposites. This issue of MRS Bulletin discusses materials innovations for realizing highly effi cient and durable electrocatalysts for large-scale, cost-effective water splitting. On the cover is a solar cell (with an electrocatalyst) that generates oxygen molecules (red) on the left electrode and hydrogen molecules (green) on the right electrode. See the technical theme that begins on p. 531.
Halide perovskite opto- and nanoelectronic materials and devices
Volume 45 - Issue 6 - June 2020
Emergent Quantum Materials
Volume 45 - Issue 5 - May 2020
The properties of quantum materials are principally defined by quantum mechanical effects at macroscopic length scales. These materials exhibit phenomena and functionalities not expected from classical physics. While quantum materials has been a topical area of modern materials science for decades, today it is at the center stage of technologies ranging from electronics, photonics, energy, defense, and sensing to environmental and biomedical applications, and, in particular, quantum information science and technology. This issue of MRS Bulletin presents important developments in emergent quantum materials at the intersection of materials science and condensedmatter physics. The cover provides a schematic view of monolayer CuO2 fi lms on a Bi-2212 substrate. See the technical theme that begins on p. 340.
Nanoscale Tomography Using X-rays and Electrons
Volume 45 - Issue 4 - April 2020
Three-dimensional (3D) tomographic imaging, using x-rays or electrons, of the structural, chemical, and physical properties of a material links the structure of a material to its processing that is central to studies across a broad spectrum of materials. In recent years, advances in technology have enabled new imaging capabilities at the nanometer or atomic scale for 3D reconstruction. This issue of MRS Bulletin discusses the development of these new techniques for nanoscale x-ray and electron tomography as well as future directions. The cover shows a 3D reconstruction of an iron (green)-cobalt (pink) oxide (gold) nanoparticle obtained using electron energy-loss spectroscopic scanning transmission electron microscopy (STEMEELS) tomography. It reveals chemical segregation and nanoscale pinholes formed in the hollow structured oxide shell induced by the Kirkendall effect during oxidation of the iron-cobalt alloy particle. (Credit: Huolin L. Xin.) See the technical theme that begins on p. 264.
Metasurfaces for Flat Optics
Volume 45 - Issue 3 - March 2020
Metasurfaces consisting of subwavelength optical antenna arrays have emerged as planar optical devices that enable many promising applications. Thesubwavelength antenna is designed to locally control the amplitude, phase, or polarization of light. Metasurfaces provide unprecedented opportunities to overcome the limitations of conventional lenses and have demonstrated promising applications, such as high-numerical aperture ultrathin lenses, high-resolution multicolor holograms, and optical skin cloaks. Metasurfaces have been developed for specifi c functionalities by exploiting new materials and design algorithms. The articles in this issue of MRS Bulletin provide a comprehensive understanding of metasurfaces and their novel applications. The cover shows the operating mechanism of a metasurface used as a lens (metalens) and a scanning electron microscope image of a particular metalens in the background. The metalens can focus light beams using phase control by the metasurface. See the technical theme that begins on p. 180.
Transient Electronic Devices
Volume 44 - Issue 2 - February 2020
Transient electronic devices. Transient electronics, that can disappear, dissolve, or degrade in a controlled manner over time, has been attracting signifi cant attention as a new and emerging technology. Transient electronics has unique applications, such as bioresorbable medical devices that can provide short-/ medium-term diagnosis and treatment without removal surgery, environmentally friendly devices that can physically decompose and produce no waste, and self-destructing devices that can provide nonrecoverable IT and military security systems. This issue of MRS Bulletin highlights recent progress in transient electronics, focusing on materials aspects, including characterization, fabrication, and applications. The cover shows the dissolution of a transient electronic device comprising an inorganic Si nanomembrane, a Mg electrode, and a SiO2 dielectric formed on a biodegradable polymer, such as silk, poly(lactic-co-glycolic acid) (PLGA), or poly(D,L-lactic acid) (PLA). All materials used for transient electronics are fully degradable into the small molecular scale, and their byproducts are biocompatible and environmentally benign. The inset images demonstrate how a transient electronic device can fully dissolve over time. Main image courtesy of S.-K. Kang, Seoul National University. Inset images courtesy of J. Koo, Northwestern University. See the technical theme that begins on p. 87.
Materials for Hot-Carrier Chemistry
Volume 45 - Issue 1 - January 2020
The promise of photoexcited hot-electron chemistry (and the complementary hot-hole chemistry) is supported by its application in many important reactions, including CO2 reduction, water splitting, hydrogenation, and coupling reactions, highlighting its potential in achieving high energy-conversion efficiency and product selectivity. Hot-electron chemistry represents a fundamentally different solar energy-conversion mechanism compared to traditional photochemistry. This issue of MRS Bulletin examines the generation and relaxation of hot electrons in typical nanoparticle systems upon light absorption and the flow of hot electrons across the surfaces of the nanoparticles. On the cover, the bottom right image is a photoexcited nanoparticle. The pairs of transparent balls with blue cores represent reactant molecules. The individual transparent balls with blue cores represent the product molecules, which are formed from the interaction of the reactant molecules with hot electrons on the surface of the nanoparticle. See the technical theme that begins on p. 20.