LiFe1−xYxPO4 doped (d-LFP) with amounts of yttrium (0.01% < x < 5% w/w) show a remarkable effect on the electrochemical behavior. The d-LPF samples were investigated on the Li extraction/insertion performance through charge/discharge and capacity–voltage curves. The best performance was attained with Y content of x = 1%. The materials were synthesized by a hydrothermal method and characterized by x-ray diffraction (XRD) and scanning electron microscopy–energy dispersive x-ray spectroscopy (SEM–EDX). The XRD studies showed that d-LPF had the same monoclinic structure as the undoped material. The achieved electrode performance has been attributed to the addition of Y3+ ion by stabilizing the orthorhomic structure. The electrode resistance decreases through the Y-doping.

Doping is a potent and often used strategy to modify properties of active electrode materials in advanced electrochemical batteries. There are several factors by which doping changes properties critically affecting battery performance, most notably the voltage, capacity, rate capability, and stability. These factors have to do specifically with changes in structure, band gap and band structure, and structural instability induced by doping. We review our recent modeling works on the effects of doping of active electrode materials, notably for prospective materials for organic and post-lithium (Na ion, Mg ion) batteries, as well as present new results, to build a coherent view on the use of n- and p-doping to modulate Li, Na, and Mg storage properties, most notably voltage. Specifically, we clearly point out effects due to electronic structure and those due to strain (structural instability), which clears some confusion about the effects of n- versus p-doping and facilitates rational rather than ad hoc design of doped materials.

The tunnel field-effect transistor (TFET) is one of the candidates replacing conventional metal–oxide–semiconductor field-effect transistors to realize low-power-consumption large-scale integration (LSI). The most significant issue in the practical application of TFETs concerns their low tunneling current. Si is an indirect-gap material having a low band-to-band tunneling probability and is not favored for the channel. However, a new technology to enhance tunneling current in Si-TFETs utilizing the isoelectronic trap (IET) technology was recently proposed. IET technology provides a new approach to realize low-power-consumption LSIs with TFETs. The present paper reviews the state-of-the-art research and future prospects of Si-TFETs with IET technology.

Human organoid models recapitulate many aspects of the complex composition and function of native organs. One of the main challenges in developing these models is the growth and maintenance of three-dimensional tissue structures and proper cellular organization that enable function. Biomaterials play an important role by providing a defined and tunable three-dimensional environment that is required for complex cellular organization and organoid growth in vitro or in vivo. This review summarizes organoids of the respiratory and digestive system, and the use of biomaterials to improve upon these model systems.

Melanin (from the Greek μέλας, mélas, black) is a biopigment ubiquitous in flora and fauna, featuring broadband optical absorption, hydration-dependent electrical response, ion-binding affinity as well as antioxidative and radical-scavenging properties. In the human body, photoprotection in the skin and ion flux regulation in the brain are some biofunctional roles played by melanin. Here we discuss the progress in melanin research that underpins emerging technologies in energy storage/conversion, ion separation/water treatment, sunscreens, and bioelectronics. The melanin research aims at developing approaches to explore natural materials, well beyond melanin, which might serve as a prototype benign material for sustainable technologies.

Sodium-ion batteries (SIBs) have received intensive attentions owing to the abundant and inexpensive sodium (Na) resource. Layered vanadium oxides are featured with various valence states and corresponding compounds, and through multi-electron reaction they are capable to deliver high Na storage capacity. The rational construction of unique structures is verified to improve their Na storage properties. This perspective provides an overview of recent advances in layered vanadium oxide for SIBs, with a particular focus on construction of novel nanostructures, and mechanism studies via in situ characterization. Finally, we predict possible breakthroughs and future trends that lie ahead for high-performance layered vanadium oxides SIBs cathode.

Recent observations on strength and deformation of small metals containing microstructures, including dislocation patterns, grain boundaries, and second-phase precipitates are reviewed. These microstructures impose an internal length scale that may interplay with the extrinsic length scale due to the specimen size to affect strength and deformation in an intricate manner. For micro-crystals containing pre-existing dislocations, Taylor work-hardening may dictate the dependence of strength on specimen size. The presence of grain boundaries in a small specimen may lead to effects far from the conventional Hall–Petch behavior. Precipitate–dislocation interactions in a small specimen may lead to an interesting weakest-size behavior.

Due to the recent outbreak of the Zika virus (ZIKV) in several regions, rapid, and accurate methods to diagnose Zika infection are in demand, particularly in regions that are on the frontline of a ZIKV outbreak. In this paper, three diagnostic methods for ZIKV are considered. Viral isolation is the gold standard for detection; this approach can involve incubation of cell cultures. Serological identification is based on the interactions between viral antigens and immunoglobulin G or immunoglobulin M antibodies; cross-reactivity with other types of flaviviruses can cause reduced specificity with this approach. Molecular confirmation, such as reverse transcription polymerase chain reaction (RT–PCR), involves reverse transcription of RNA and amplification of DNA. Quantitative analysis based on real-time RT–PCR can be undertaken by comparing fluorescence measurements against previously developed standards. A recently developed programmable paper-based detection approach can provide low-cost and rapid analysis. These viral identification and viral genetic analysis approaches play crucial roles in understanding the transmission of ZIKV.

In the recent years, several investigators are incorporating nanotechnology, one of the most powerful trendsetters in material research, to conventional polymer prepregs to enhance mechanical properties of composite strucutures. The current paper outlines the role of nanotechnology in reinforcing resin and challenges for fabricating nanomaterial reinforced prepregs. As delamination is the most critical problem for composite materials, the current study only focuses the application nanotechnology as a possible solution to alleviate delamination problems in laminated composites. The importance of nanoengineered prepregs is discussed in a viewpoint of improvement in interlaminar properties of the laminated composite materials.

Recent years have seen an increased application of small-scale uniaxial testing—microcompression—to the study of plasticity in macroscopically brittle materials. By suppressing fast fracture, new insights into deformation mechanisms of more complex crystals have become available, which had previously been out of reach of experiments. Structurally complex intermetallics, metallic compounds, or oxides are commonly brittle, but in some cases extraordinary, though currently mostly unpredictable, mechanical properties are found. This paper aims to give a survey of current advances, outstanding challenges, and practical considerations in testing such hard, brittle, and anisotropic crystals.

Considered as a less hazardous piezoelectric material, potassium sodium niobate (KNN) has been in the fore of the search for replacement of lead (Pb) zirconate titanate for piezoelectrics applications. Here, we challenge the environmental credentials of KNN due to the presence of ~60 wt% Nb2O5, a substance much less toxic to humans than Pb oxide, but whose mining and extraction cause significant environmental damage.

The diverse and fascinating properties of transition metal oxides stem from the strongly correlated electronic degrees of freedom; the scientific challenge and range of possible applications of these materials have caused fascination among physicists and materials scientists, thus capturing research efforts for nearly a century. Here, we focus on the binary V x O y and the ternary perovskite AVO3 and review the key aspects from the underlying physical framework and their basic properties, recent strides made in thin-film synthesis, to recent efforts to implement vanadium-based oxides for practical applications that augment existing technologies, which surpass limitations of conventional materials.

Self-assembly of multiferroic oxide composites by chemical and biochemical methodology is discussed. The approach involves covalently attaching organic functional groups or oligomeric DNA/RNA to the nanoparticles (NPs). The organic functional groups are only reactive toward functional groups located on different NPs. Using oligomeric DNA/RNA, one could program NPs to only interact with particles possessing complementary DNA/RNA. We have applied both concepts to the assembly of nanostructures with ferrites for the ferromagnetic phase and barium titanate for the ferroelectric phase. The assembled core–shell particles and superstructures obtained in a magnetic field show evidence for strong interactions between the magnetic and ferroelectric subsystems.

Three-dimensional (3D) printing generates cellular architected metamaterials with complex geometries by introducing controlled porosity. Their ordered architecture, imitative from the hierarchical high-strength structure in nature, defines the mechanical properties that can be coupled with other properties such as the acoustic, thermal, or biologic response. Recent progress in the field of 3D architecture materials have advanced that enables for design of lightweight materials with high strength and stiffness at low densities. Applications of these materials have been identified in the fields of ultra-lightweight structures, thermal management, electrochemical devices, and high absorption capacity.

Nanostructured cerium oxide (CeO2) with outstanding physical and chemical properties has attracted extensive interests over the past few decades in environment and energy-related applications. With controllable synthesis of nanostructured CeO2, much more features were technologically brought out from defect chemistry to structure-derived effects. This review highlights recent progress on the synthesis and characterization of nanostructured ceria-based materials as well as the traditional and new applications. Specifically, several typical applications based on the desired ceria nanostructures are focused to showcase the importance of nanostructure-derived effects. Moreover, some challenges and perspectives on the nanostructured ceria are presented, such as defects controlling and retainment, scale-up fabrication, and monolithic devices. Hopefully, this review can provide an improved understanding of nanostructured CeO2 and offer new opportunities to promote the further research and applications in the future.

Among various material nanoarchitectures, the nanotube geometry has received incredible attention due to the unique properties provided by its high surface area as well as nanoscale wall thickness and the availability of a variety of techniques to fabricate them. Since the beginning of this century, anodization has emerged as one of the most effective techniques for the fabrication of functional oxide nanotubes. Oxide nanotubes of a number of metals and alloys have been developed using this versatile technique. We review here the research activities on anodic nanotubes of various binary, ternary, and multinary materials and their selected applications.

Multiferroic nanostructures have been attracting tremendous attention not only for novel phenomena associated with fundamental physics, but also due to exciting application potentials in future nanoelectronic devices. In this mini-review, we first introduce several fabrication techniques recently developed for single phase and composite multiferroic nanostructures. Then, the topologic vortex domain structures in various ferroic nanostructures, which may bring about additional fundamental discoveries and applications in ultrahigh density recording, are discussed. Particular attention is paid to magnetoelectric effects in multiferroic nanodots, including room temperature electric field induced magnetic domain switching. Finally, existing challenges and new directions, e.g., cross-couplings among multiple functionalities, are prospected. We genuinely hope that this mini-review will arouse the readers' interest in this fascinating field.

Nanomaterials have been intensively studied over the past decades with many advantages over traditional bulk materials in many applications. Nanomaterials' properties are largely governed by their chemical compositions, sizes, shapes, dimensions, morphologies and structures, which are primarily controlled with the chemical and/or physical fabrication methods and processes. This prospective will highlight recent progress on the modifications of oxide nanomaterials' properties by hydrogenation, namely heat treatment under hydrogen or hydrogen plasma environment, for various applications.

We use first-principles calculations based on density functional theory to investigate the interplay between oxygen vacancies, A-site cation size/tolerance factor, epitaxial strain, ferroelectricity, and magnetism in the perovskite manganite series, AMnO3 (A = Ca2+, Sr2+, Ba2+). We find that, as expected, increasing the volume through either chemical pressure or tensile strain generally lowers the formation energy of neutral oxygen vacancies consistent with their established tendency to expand the lattice. Increased volume also favors polar distortions, both because competing rotations of the oxygen octahedra are suppressed and because Coulomb repulsion associated with cation off-centering is reduced. Interestingly, the presence of ferroelectric polarization favors ferromagnetic (FM) over antiferromagnetic (AFM) ordering due to suppressed AFM superexchange as the polar distortion bends the Mn–O–Mn bond angles away from the optimal 180°. Intriguingly, we find that polar distortions compete with the formation of oxygen vacancies, which have a higher formation energy in the polar phases; conversely the presence of oxygen vacancies suppresses the onset of polarization. In contrast, oxygen vacancy formation energies are lower for FM than AFM orderings of the same structure type. Our findings suggest a rich and complex phase diagram, in which defect chemistry, polarization, structure, and magnetism can be modified using chemical potential, stress or pressure, and electric or magnetic fields.

When two materials interact, the processes between the phases determine the functional properties of the compound. Pivotal interface phenomena are diffusion and redistribution of atoms (molecules). This is especially of interest in Lithium ion batteries where the interfacial kinetics determines the battery performance and impact cycling stability. A new phase field model, which links the atomistic processes at the interface to the mesoscale transport by a redistribution flux controlled by the so called ‘interface permeability’ was developed. The model was validated with experimental data from diffusion couples. Calculations of the concentration profiles of the species at the electrode–electrolyte interface are reported. Active particle size, morphology and spatial arrangement were put in correlation with diffusion behavior for use in reverse engineering.