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Micromagnetic structure and coercivity were systematically investigated by electron holography and micromagnetic simulation. The experimental data show that the distribution of magnetic flux lines of FeCo-rich (α1) phase is different from that of AlNi-rich (α2) phase. Quantitative analysis based on the measurement of electron holography show that the magnetizations and coercivities of α1 phases for 36Co and 40Co are calculated to be 11.0 kG and 8.5 kG, 1848 Oe and 3029 Oe, respectively. Further micromagnetic simulations reveal that the decrease of α1 phase diameters and the weakened exchange coupling (increased distance) between adjacent phases are critical factors to increase the coercivities of AlNiCO magnets, well matching with the measured results from electron holography. [ABSTRACT FROM AUTHOR]

• All-inorganic PSCs include counter electrodes (CEs) comprising carbonized biomass. • CEs combine carbonized bacterial cellulose or macadamia nutshell with carbon paste. • A CE modified with carbonized macadamia nutshell (CMNS) improved PCE by 140%. • CMNS had an outstanding SSA, a suitable WF, and reduced the resistivity of the CE. • A CE modified with CMNS improved the long-term thermal stability of the PSC. [Display omitted] The cost associated with hole-transporting materials (HTMs) and electrodes made of noble metals is a recurrent problem for the widespread application of perovskite solar cells (PSCs). Biomass-derived carbons are green materials that have been incorporated in the electrodes of diverse electrochemical devices to reduce cost, improve environmental sustainability, and augment the specific surface area (SSA). Here, carbonized bacterial cellulose (CBC) and carbonized macadamia nutshell (CMNS) were combined with commercial carbon paste (CP) to fabricate counter electrodes (CEs) integrated into highly-stable all-inorganic CsPbBr 3 PSCs synthesized by thermal evaporation. When electrically-conductive CP was mixed with either 0.1% CBC or CMNS, the power conversion efficiency was improved to 4.76% and 6.18%, respectively, compared to 4.45% for a PSC equipped with pure CP. The better performance of CMNS versus CBC in the CEs can be explained by a larger SSA, a more suitable work function, and a lower sheet resistance. The outstanding surface area of CMNS is likely to improve hole scavenging efficiency in the PSCs by increasing the number of contacts with CsPbBr 3. The long-term stability of the all-inorganic CsPbBr 3 PSC at high temperature was also improved with the CP CE modified with CMNS. These results demonstrate that adding CBC or CMNS to CP for the fabrication of CEs in a suitable ratio improves the photoelectric properties of all-inorganic PSCs and thus opens possibilities for novel applications for renewable and earth-abundant biomass-derived carbons. [ABSTRACT FROM AUTHOR]

• Selectivity control in CO 2 photoreduction to methane or methanol is an issue that needs to be solved. • A novel trimetallic LDH system containing Ni, Ti and Al cations was synthetised with a nanoball superstructure morphology. • The selectivity towards methane was 86%, under solar simulator conditions, with a production of 148 µmol g-1 h-1. [Display omitted] Layered double hydroxides is a rising family of materials with interesting photocatalytic properties that are starting to be employed on the CO 2 photoreduction to useful chemicals. However, the selectivity control towards high energy value products, such as methane or methanol, is one of the main issues of this process due to the easier formation of CO, which requires fewer electrons to be transferred, and the competition of hydrogen evolution reaction. In this work, a new LDH material containing Ni, Ti and Al within the structure was synthesised with the purpose of increasing the selectivity towards methane production. The material was tested under solar simulator conditions, yielding a methane production of 148 µmol g-1 h-1, with a selectivity of 86%, one of the highest values reported for this kind of material, while the competition from hydrogen evolution was almost suppressed. The role of Ti directing the selectivity towards methane was confirmed, since no CH 4 was produced when NiAl-LDH catalyst was used instead. [ABSTRACT FROM AUTHOR]

• Titanium plasma ion implanted hematite photoanodes with improved PEC water splitting performance were fabricated. • Improved charge carrier transport induced by Ti doping reduces carrier recombination loss, thus enhances photoactivity. • This work provides new insights into surface-engineered photo-responsive semiconductors for emerging hydrogen technology. Energetic titanium plasma ion implantation technique is used to modify hematite (α-Fe 2 O 3). Ti implanted α-Fe 2 O 3 nanoporous film shows enhanced photoelectrochemical water oxidation performance, compared to bare α-Fe 2 O 3. [Display omitted] Hematite (α-Fe 2 O 3) is recognized as a promising photoelectrode material for photoelectrochemical (PEC) water splitting, as a result of its abundance, non-toxicity, suitable bandgap, and photochemical stability. Nevertheless, the undesirable physical and photophysical behaviors, such as poor conductivity, short diffusion length, and rapid charge-carrier recombination, seriously restrict PEC water splitting efficiency of hematite semiconductors. Herein, we fabricate nanoporous titanium (Ti)-doped α-Fe 2 O 3 thin films by a facile hydrothermal reaction, subsequently utilizing energetic plasma ion implantation with a post-annealing process to significantly enhance the photoelectrochemical water oxidation performance of hematite. On the basis of materials characterization and electrochemical analysis, the optimized Ti-doped Fe 2 O 3 , i.e., Ti-4-Fe 2 O 3 , exhibits improved photocurrents of 0.55 and 1.07 mA cm−2 at 1.23 and 1.5 V versus RHE respectively under illumination of 100 mW/cm2 with AM 1.5 G spectrum, showing approximately 1.6-fold increases compared to pristine Fe 2 O 3. We attribute this increase to improved charge carrier transport induced by Ti doping that reduces the recombination of light-driven charge carriers. The work utilizing plasma-assisted doping technique provides new insights into the surface engineering of photo-responsive semiconductors for the development of emerging hydrogen technologies. [ABSTRACT FROM AUTHOR]

Directed energy deposition (DED) process can enable rapid and low-cost manufacturing of large-scale high-strength AA2219 Al-6.3 wt%Cu alloy components, displaying broad prospects for structural lightweighting in aerospace applications. However, a high tendency to prominent porosity defects and inhomogeneous layered microstructure are intrinsically present in DED-processed Al-Cu alloy, leading to significant performance degradation and anisotropy. Herein, we demonstrate a robust DED process to fabricate high-quality formed AA2219 alloy deposits, based on in-situ synthesized TiC-containing wires and an ultrasonic-frequency pulsed (UFP) arc. The effects of in-situ synthesized submicron-scale TiC particles (average diameter 0.7 ± 0.4 µm) in microstructural evolution and mechanical performance were comparatively investigated through multi-scale microstructural characterization and mechanical property measurement. The introduction of TiC particles into the as-deposited AA2219 component results in a homogeneous refined equiaxed microstructure with an average α-Al grain diameter of 23.4 ± 2.9 µm, and a dramatical elimination of porosity defects. After undergoing a T6 solution and aging treatment, the TiC-reinforced AA2219 deposit demonstrates excellent resistance against grain coarsening, porosity defects growth, and particle segregation. Moreover, the introduced TiC particles lead to a noticeably enhanced precipitation hardening behavior. A homogeneous precipitation microstructure of dispersed θ′-Al 2 Cu particles with an average diameter of 84.1 ± 34.5 nm and a high fraction of 9.8 ± 2.5 vol% was obtained in the heat-treated AA2219 deposit. Based on the as-built multiscale homogeneous microstructure, the heat-treated deposit embedded with TiC particles exhibits a synergy of unprecedented tensile strength of 501 ± 14 MPa and excellent ductility of 9.6 ± 3.3%. [Display omitted] • A well-formed AA2219 alloy was fabricated via wire+arc directed energy deposition. • Introducting TiC particles results in homogeneous refined equiaxed microstructure and suppressed porosity. • Heat-treated TiC p /2219 deposit exhibits a synergy of strength and ductility. [ABSTRACT FROM AUTHOR]

Abstract Multilayered Cu/CoCu metal-conductors were prepared by alternatively electrodepositing Cu and CoCu layers in the same electrolyte. The relationships between the phase structure, surface roughness, magnetic properties and the plating potential have been studied in details. Soft CoCu layers with low coercivity were obtained by selecting proper additives, which allowed the introduction of in-plane uniaxial magnetic anisotropy and negative permeability above 1.5 GHz. A transmission line consisting of 10 CoCu/Cu bilayers with near zero effective permeability was then designed and fabricated, which yielded >80% lower resistance at 10 GHz compared to a Cu transmission line in the same dimensions. This study offers a novel metal-conductor with suppressed eddy current loss and a low-cost method for next generation RF electronics. Highlights • Tuning phase structure, lattice constant and magnetization by plating potential. • Introduction of the uniaxial magnetic anisotropy to obtain negative permeability. • Electrodeposition of CoCu/Cu multilayered films in the same electrolyte. • Demonstration of a wideband resistance drop up to 82%. [ABSTRACT FROM AUTHOR]

SrTiO 3 thin films were deposited onto Pt (100)/Ti/SiO 2 /Si and fused silica substrates by sol–gel and spin-coating technology. The crystallinity of the films may be adjusted by means of the annealing temperatures. The electronic band structure of the thin films was analyzed by UV–vis spectrophotometer, indicating that the band structure of the amorphous and crystalline SrTiO 3 thin films were quite different. The surface chemical states of the thin films were analyzed by X-ray photoelectron spectroscopy (XPS), indicating that the defect structures of the amorphous and crystalline SrTiO 3 thin films were apparently different. Photoelectric and dielectric properties of the thin films were measured using electrochemical workstation and LCR meter, respectively. The results show that crystallization of the films, an effective way of defect modulation, makes significant influence on the semiconducting property of the SrTiO 3 thin films. From the perspective of the defect structure, the essential difference between amorphous and crystalline SrTiO 3 thin films was analyzed. 750 °C was found to be an optimum annealing temperature for obtaining dense and homogeneous SrTiO 3 thin films with a photocurrent density of 1.1 μA/cm 2 . [ABSTRACT FROM AUTHOR]

• Develop a facile and controllable pyrolysis strategy to synthesize the NiCo alloys. • A unique heterostructure between NiCo alloy and mixed NiCo-based sulfides were constructed. • The NiCoS coating improves the conductivity of the NiCo-NiCoS@NC nanoparticles. • The NiCo alloy and NiCoS act as trapping-diffusion-conversion sites of polysulfides. • A superior rate capacity of 692 mA h g−1 can be achieved at a high current density of 5 C. The transition-metal-based alloy and chalcogenides have been widely investigated as efficient sulfur host for lithium sulfur batteries (LSB), yet the synergistic effect of both has been rarely reported. Herein, nickel cobalt alloy (NiCo) and nickel cobalt sulfides (NiCoS) have been simultaneously constructed on the nitrogen-doped carbon substrate (NiCo-NiCoS/NC) via facile calcination-sulfurization of NiCo Prussian blue analogue (NiCo-PBA). The abundantly exposed NiCo alloy and NiCoS domains act as adsorption and catalytic sites that enable effective capture and catalytic conversion of polysulfides, and the highly conductive NiCo-NiCoS integrated with N-doped carbon provides a facile Li+ transfer channel. As a result, S@NiCo-NiCoS/NC electrode delivers a high initial discharge capacity of 1345.1 mA h g−1 at the current density of 0.1 C, superior rate capability of 692.1 mA h g−1 up to 5 C, and ultralong lifespan over 1500 cycles with a small capacity decay of 0.055% per cycle at the current density of 1.0 C. [ABSTRACT FROM AUTHOR]

In the present study, monodisperse NdOCl nanocubes with single-crystalline structure were fabricated through a novel nonhydrolytic colloidal route, in which NdCl 3 ⋅6H 2 O was only used as the neodymium source and oleylamine was the coordinating ligand as well as the surfactant. TEM image indicates that the nanostructures show cubic shape with an edge length of about 27 nm. XRD pattern and SAED analysis of numerous nanocubes indicate that the NdOCl nanocubes have a pure tetragonal PbFCl matlockite phase. HRTEM image and FFT pattern of individual NdOCl nanocubes reveal that each cube is single crystalline. Magnetization analysis suggests that the NdOCl nanocubes show ferromagnetic characteristic at room temperature. These results are significant for the investigations of rare earth-based nanocrystals. Besides, this novel nonhydrolytic colloidal route is believed to be a potential general strategy for the synthesis of monodispersed rare earth oxychlorides nanocrystals. [ABSTRACT FROM AUTHOR]

Highlights: [•] Y2O2S: Yb, Er shows excellent red emission under 1550nm excitation exceeds. [•] The adjustment of emission colour in a very wide range has been realized. [•] Two-tone upconversion colour can be created. [ABSTRACT FROM AUTHOR]

Highlights: [•] The long-afterglow material is process-dependent. [•] We adopt a modified sulphide-fusion route to synthesise Y2O2S:Eu,Mg,Ti. [•] The afterglow results from Ti-related defects and Ti also creates harmful defects. [•] The Mg2+ ions effectively modulate the depth and concentration of the traps. [•] The codoping of Mg2+–Ti4+ ion pairs reduces the harmful defects. [Copyright &y& Elsevier]

Highlights: [•] We demonstrated that the solvent plays a critical role in the nanotubes formation process which can be controlled by the ambient temperature. [•] For a selected solvent, the saturated vapor pressure was the intrinsic factor for the morphologies determining during the electrospinning process. [•] The formation process of nanotubes was observed by TEM and a possible formation mechanism was proposed. [•] The magnetic properties of magnesium ferrite calcined at different temperature stages were systematically studied. [ABSTRACT FROM AUTHOR]

• A composite with MoNi 4 alloys embedding into MoO 3-x porous nanorods was synthesized via a simple in-situ reduction method. • The obtained MoNi 4 @MoO 3-x exhibits a remarkable HER activity with 10 mA/cm2 constant current under 58.6 mV low overpotential. • The remarkable HER activity is found to originate from the MoNi 4 alloys, excellent conductivity and porous structure. [Display omitted] Hydrogen evolution reaction (HER) in alkaline media is expected to become a renewable and economical technology for hydrogen production. Various non-noble electrocatalysts have been explored for HER, in which Ni-Mo alloy is one of the best media. However, its syntheses are complicated and costly. In this work, we contribute an in-situ reduction method of porous MoNi 4 @MoO 3- x nanorods. The synthesized MoNi 4 @MoO 3- x exhibits a remarkable HER activity with 10 mA/cm2 constant current under 58.6 mV extremely low overpotential, small Tafel slope of 44.8 mV/decade, and high durability in 1 M potassium hydroxide electrolyte. Its remarkable activity is found to originate from the highly activity of MoNi 4 , excellent conductivity and favorable porous structure. This work is believed to provide a promising strategy for the HER development of highly active and cost-effective electrocatalysts. [ABSTRACT FROM AUTHOR]

• The insertion of an MgO buffer layer significantly reduces the large lattice mismatch between FeRh and PMN-PT. • The FeRh(001) film is epitaxially grown on the ferroelectric PMN-PT(001) substrate. • The epitaxial FeRh(001) film displays multi-step hysteresis loops at various field orientations at 350 K. • The butterfly shape of coercivity vs electric field indicates a strain-mediated magnetoelectric coupling. • The transition temperature and the magnetization are enhanced and reduced in the remnant polarization state, respectively. We epitaxially grew the metamagnetic FeRh films on ferroelectric PMN-PT(001) substrates and investigated the electric control of magnetic properties. An MgO buffer layer is inserted to reduce the considerably large lattice mismatch of 5.44% between FeRh and PMN-PT, leading to a nice epitaxial growth with a relationship of FeRh[110](001)||MgO[100](001)||PMN-PT[100](001). The as-grown FeRh film shows a typical antiferromagnetic-to-ferromagnetic phase transition by means of varying the temperature. Because a growth-induced uniaxial magnetic anisotropy is superimposed on the in-plane four-fold magnetocrystalline anisotropy, the epitaxial FeRh film displays different kinds of multi-step hysteresis loops at various field orientations. An electric field applied on the PMN-PT substrate can remarkably increase the coercivity of FeRh film, which presents a butterfly type shape, indicating a strain-mediated magnetoelectric coupling. Because of the inhibitory effect of the remnant compressive strain on the phase transition, the critical transition temperature and the magnetization are obviously enhanced and reduced, respectively, after removing the electric effect. [ABSTRACT FROM AUTHOR]

This work reports the synthesis of size-controlled and well-dispersed CoFe 2 O 4 nanocrystals through a facile thermal decomposition method, of which size can be simply tuned via the change of reaction time. The fcc Co or hcp Co impurities can be precipitated out in the CoFe 2 O 4 nanocrystals by further prolonging the reaction time. Magnetic measurements show that the pure CoFe 2 O 4 nanocrystals show size-dependent ferrimagnetism at room temperature, in which the saturation magnetization increases and the coercivity anomalously decreases as the particle size increases. The variation of magnetic properties is attributed to the surface-randomized spin and cations redistribution caused by surface effect and size effect. Besides, the precipitated Co impurities can greatly improve the saturation magnetization and coercivity of the CoFe 2 O 4 nanocrystals. This paper provides a new path to tailor the magnetic properties of spinel ferrite nanostructures by tuning the cations distribution or adding magnetic impurities. • Size controllable CoFe 2 O 4 nanocrystals with single magnetic domain were prepared. • The CoFe 2 O 4 nanocrystals show size-dependent room temperature ferrimagnetism. • The anomalous Hc trend is due to the redistribution of Co2+ caused by size effect. • Co impurities can greatly improve the magnetic properties of CoFe 2 O 4 nanocrystals. [ABSTRACT FROM AUTHOR]