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The oxidation resistance and tribological behavior of CrAlN/SiN x multilayer films with different interface structures were investigated. The multilayer film exhibited better oxidation resistance than the monolithic CrAlN film after oxidation at 900 °C and 1000 °C for 10 h. The crystalline SiN x sublayer was beneficial to oxidation resistance at 900 °C in contrast to the trend observed after oxidation at 1000 °C. The stacking faults generated in the multilayer film were induced by the oxidation of SiN x. The diffusion mechanism changed from the outward diffusion of cations to an inward diffusion of anions when the temperature was increased to 1000 °C. The multilayer film with a crystalline interface exhibited lower coefficient of friction (COF) and better tribological properties than the CrAlN film and multilayer with an amorphous interface. [ABSTRACT FROM AUTHOR]

• Based on the Euler-Lagrange framework, a three-dimensional transient heat-mass transfer model of silicon particle melting/migration coupled with turbulent heat transfer in the silicon melt during CCZ monocrystalline silicon growth was developed using large eddy simulation method. • The heat exchange between silicon particles and their own melt, as well as the changes in particle size during their melting/migration were considered. • The influences of key feeding particles parameters such as the feeding temperature, feeding particle size, and feeding speed on the melting/migration characteristics of silicon particles and the melt temperature were firstly revealed in detail. The Continuous Czochralski (CCZ) is a promising approach for preparing low-cost high-quality monocrystalline silicon in the photovoltaic field. To investigate the coupled mechanism of silicon particles melting/migration and melt turbulent heat transfer during the CCZ monocrystalline silicon growth, based on the Euler–Lagrange framework, a three-dimensional transient heat-mass transfer model is developed using the LES method considering the heat exchange between the silicon particles and the silicon melt as well as the particles size change. In addition, we investigated the effects of key silicon particle parameters such as feeding temperature, particle size and feeding speed, on the silicon particles melting/migration and melt turbulent heat transfer. The results show that appropriately increasing the feeding temperature and speed contributes to achieve more concentrated particles distribution and weaken the movement of silicon particles towards the crystalline interface simultaneously, which conduce to eliminate the adverse impact of continuous feeding on monocrystalline silicon growth. And the feeding temperature has a great effect on the temperature fluctuation near the crystalline interface. In addition, when the feeding speed exceeds 1.5m/s, increasing feeding speed has no significant effect on the particles distribution and melting process. Besides, the feeding particle size has a significant effect on the maximum penetration depth of particles. The small silicon particles prefer moving to the crystalline interface driven by thermophoretic force, which is detrimental to the high-quality CCZ monocrystalline silicon growth. [ABSTRACT FROM AUTHOR]

Sodium ion batteries (SIBs) have garnered more and more attentions owing to the uneven distribution and increasing price of lithium mineral. Herein, BiVO 4 –V 2 C endogenous heterostructures as anode for SIBs are synthesized via one-step in situ hydrothermal method. The designed hydrangea-like heterostructure ensures a wide contact surface for the interaction of anode material with the electrolyte, and endows stable heterojunction interfaces between BiVO 4 and V 2 C MXene, the synergistic effect of which significantly improves the electrical conductivity, pseudo-capacitance and alleviates the volumetric change of BiVO 4 during charge/discharge process. Density functional theory (DFT) calculations ulteriorly demonstrate that the electric field at the BiVO 4 –V 2 C interface contributes to the excellent Na ion diffusion kinetics and impressive sodium storage capacity. As a result, the BiVO 4 –V 2 C anode achieved outstanding performance with a high discharge capacity (480 mAh g−1 after 600 cycles at 0.2 A g−1), and impressive long-term lifespan (303 mAh g−1 over 2000 cycles at 1 A g−1). This work reveals a new design of novel V 2 C MXene heterojunctions which coupling with BiVO 4 combined with the analysis of amorphous/crystalline interface, developing a proper strategy for the effective energy storage of sodium. An endogenous heterostructure of BiVO 4 coupled with V 2 C MXene (BiVO 4 –V 2 C) is developed via a one-step hydrothermal method. The designed hydrangea-like heterostructure provides a large surface area for the contact of the electrode material with electrolyte, and endows stable heterojunction interfaces between BiVO 4 and V 2 C, which significantly improves the reaction kinetics. [Display omitted] • Hydrangea-like endogenous BiVO 4 –V 2 C heterostructure is firstly reported. • Internal micro-electric field for improving Na+ migration and reaction kinetics. • The electrode delivers superior specific capacity and excellent cycle stability. • Endogenous heterostructure offers new insights for MXenes heterojunctions design. [ABSTRACT FROM AUTHOR]

[Display omitted] • Anthracene-appended poly(ʟ-lactide)s (AAP) were synthesized by ROP of ʟ-lactide. • The excimer emission was observed in the low molecular weight AAP. • The monomeric emission is observed in amorphous and single crystals of AAP. • In crystallized AAP, fluorescence arises from anthracene excimers and monomers. • In the gel state AAP (e form), only the excimer emission was observed. The design and development of solid-state excimer-emitters bear great potential for attaining efficient solid-state luminescent materials. In this study, we have synthesized anthracene-appended poly(ʟ-lactide)s (AAPs) to regulate the arrangement of anthracene moieties by controlling the crystallization and polymorphic form of covalently linked poly(ʟ-lactide) (PLLA). In the high molecular weight AAP, the fluorescence intensity mainly arises from the monomeric anthracene moieties, whereas in the low molecular weight AAP, the excimer emission was observed depending on the structure and morphology of covalently-linked PLLA. The monomeric emission is predominantly observed in amorphous polymer due to the molecular level dispersion of covalently-linked anthracene moieties throughout the polymer matrix. When the polymer was crystallized under different conditions, covalently-linked anthracene moieties were excluded from polymer crystals or crystalline lamellae and are located on the surface or at the interface, which is advantageous for regulating the geometry of anthracene moieties. In the case of single crystals of PLLA, covalently-linked anthracene moieties assemble on the surface and emit mainly in their monomeric state due to the lack of π-stacking. In the melt-crystallized sample (α form), covalently-linked anthracene moieties reside at the interface of crystalline and amorphous domains by either dipolar interactions or π-stacking and fluorescence arising from anthracene excimers and monomers. In the gel state (ε form), only the excimer emission was observed due to the effective interactions between the anthracene moieties in the presence of excess solvent in the amorphous domains. In this way, polymer crystallization played a significant role in determining the arrangement of covalently-linked anthracene moieties in AAP. This study reveals the role of polymer crystallization on the excimer evolution in fluorophore-appended semicrystalline polymers and provides new insight into the design and development of fluorophore-appended polymers for optoelectronic devices. [ABSTRACT FROM AUTHOR]

Bismuth telluride-based thermoelectric (TE) devices were widely used in waste heat recovery due to their high thermoelectric figure of merit (ZT), but the severe diffusion between Sn-based solder and TE pillar generated porous and brittle Sn-Te intermetallic compound (IMC), which seriously restricted the reliable service of devices. Ni-based coating was used but the thick Ni-Te IMC also impaired the properties of TE pillars. In this work, the crystalline Co-P coating was inserted between the p-type TE material Bi 0.5 Sb 1.5 Te 3 and the solder by electrodeposition, and the power generation sustainability of the TE pillar were significantly improved, and the mechanism was revealed. The microstructural characterization proved that the Co-P coating could effectively resist the diffusion of active Sn, Bi, Sb, Cu atoms. Co-P coating would provide support for the structural integrity and performance sustainability of TE pillars. It was worth noting that an ultrathin CoTe 2 IMC layer was formed between the Co-P coating and the Bi-Sb-Te pillar, which was much thinner than the Ni-Te IMC layer reported in the literature. This indicated that Co-P only consumed little thermoelectric elements, but also a good metallurgical bond was formed between the Co-P and the Bi-Sb-Te. After aging at 423 K for 150 h, the maximum output power and average Seebeck coefficient of the TE pillar without coating dropped significantly by 74% and 34%, respectively, and the internal resistance rose by 67%. Remarkably, the maximum output power and average Seebeck coefficient of the TE pillar protected by the Co-P coating only decreased by 14% and 5%, respectively, and the internal resistance only increased by 6%. [Display omitted] • Co-P coating showed a remarkable effect on the sustainability of TE power generation. • Co-P coating could effectively resist the diffusion of active Sn, Bi, Sb, Cu atoms. • An ultrathin CoTe 2 IMC layer was formed between the Co-P coating and the TE pillar. • Co-P coating consumed less thermoelectric elements than Ni-based coating. [ABSTRACT FROM AUTHOR]

Nano-porosity in amorphous Ge formed by swift heavy ion irradiation displays a peculiar self-organisation process. Initially almost randomly distributed pores grow with increasing irradiation fluence and segregate in layers orientated parallel to the sample surface. This self-organisation mechanism depends on the ion energy, thickness of the amorphous Ge layer and the angle of ion incidence and shows a characteristic length depending on ion energy and irradiation angle. Molecular dynamics simulations of individual ion tracks show that voids form due to the transition from the low-density amorphous to the high-density liquid phase, which also gives rise to a flow directed away from large pores and surfaces. The flow results in a characteristic distance from surfaces and larger pores, below which new voids do not form, and supports the formation of voids at the amorphous/crystalline interface. Simulations also demonstrate that, while direct impacts can reposition small voids, partial or nearby impacts promote their growth at the same location. These processes are plausible drivers for the self-organization. [Display omitted] [ABSTRACT FROM AUTHOR]

Order/dis-order atomic arrangements in crystalline/amorphous structure possess a complementing effect in electro-catalysis as the former one can offer a long-range electronic conducting path, whereas the latter is rich with active sites. However, atomic level interfacing of crystalline and amorphous structures is extremely challenging and thus often end-up with uncontrolled secondary deposition one above another. Here, we are reporting second-scale atomic rearrangement of crystalline oxide nanowire surface into amorphous molybdenum sulfide shell that displayed excellent hydrogen evolution activity. Employing transient heating by microwave-activated graphene filament, surface atoms of molybdenum tungsten oxide (MoWO) nanowire can be arrested in either an amorphous or crystalline state during their sulfidation. Such a nanowire structure consisting of crystalline oxide core-amorphous sulfide shell shows excellent catalytic activity for hydrogen evolution reaction (HER) and exhibits an overpotential of 136 mV at 10 mA cm−2 in the acid electrolyte, which is much lower than the overpotential of parent oxide nanowire (356 mV) and its fully sulfurized crystalline counterpart (163 mV). As-developed catalyst also shows competitive HER performance with excellent alkaline and neutral electrolytes stability, thereby qualifying it as a pH universal catalyst. A detailed density functional theory calculation reveals oxide core promoted activation of multiple sites of amorphous sulfide phase, which provide key insights of electronic modulation via crystalline/amorphous interfacial structure for HER catalysis. This rapid and highly facile technique can lay the platform for the development of generic crystalline/amorphous core-shell nanostructure and their possible use as cost-effective and efficient catalysts. [Display omitted] • The unique microwave-induced second-scale surface amorphization is demonstrated. • Amorphous@crystalline core-shell nanowire of a-MoS x @MoWO structure was realized. • The a-MoS x @MoWO exhibits excellent pH-universal HER activity. • Synergy between core and shell for HER is studied by detailed DFT calculation. • Crystalline core turns multiple inactive sites of amorphous shell to highly active. [ABSTRACT FROM AUTHOR]

Transition metal borides have shown great promise as a supercapacitor electrode material. However, the amorphous structure of metal borides leads to the structural collapse of electrode material during electrochemical cycling, which seriously affects the stability of the material. In the present work, we successfully construct amorphous/crystalline NiCoB@NiCo 2 S 4 heterogeneous interfacial composites by introducing the outer layer of sulfide to improve the electrochemical performance. NiCoB@NiCo 2 S 4 shows a specific capacitance of 1562 F g−1 at a current density of 1 A g−1 and still possesses 58% specific capacitance even at a higher current density of 50 A g−1. The asymmetric supercapacitor (ASC) device assembled with Bi 2 O 3 @C as the negative electrode and NiCoB@NiCo 2 S 4 as the positive exhibits a high energy density of 98.75 Wh kg−1 at a power density of 750 W kg−1. The ASC also exhibits excellent cycling stability with capacitance retention of 118% after 10000 cycles at a current density of 10 A g−1, which fully demonstrates the practical applications value of NiCoB@NiCo 2 S 4 //Bi 2 O 3 @C. The amorphous/crystalline NiCoB@NiCo 2 S 4 heterogeneous interfacial composites were successfully constructed for the first time. The resulting amorphous/crystalline heterogeneous interface effectively improves the electron/ion transport rate and increases the electrochemical reactive sites. The assembled NiCoB@NiCo 2 S 4 //Bi 2 O 3 @C asymmetric supercapacitors exhibit a high energy density of 98.75 Wh kg−1 due to the high specific capacitance potential of NiCoB@NiCo 2 S 4 and Bi 2 O 3 @C. The introduced crystalline outer cladding metal sulfide effectively inhibits the oxidation of the metal boride core, thus exhibiting excellent electrochemical cycling stability. [Display omitted] • Amorphous/crystalline NiCoB@NiCo 2 S 4 interface structure was firstly constructed. • NiCoB@NiCo 2 S 4 showed 1562 F g−1 at 1 A g−1. • The ASC had a high energy density of 98.75 Wh kg−1. [ABSTRACT FROM AUTHOR]

Microstructures and mechanical properties of Ni matrix composites reinforced with amorphous SiO 2 particles by in-situ pyrolysis of polycarbosilane (PCS) coated on Ni powders were studied in this paper. The submicron spherical amorphous SiO 2 particles instead of traditional SiC uniformly distributing in the composites result from the generated silicon source by PCS pyrolysis combined with oxygen impurity in the preparation. The prepared composites achieve high yield strength, 172 MPa, and ultimate tensile strength, 494 MPa, as well as outstanding ductility, total elongation 28.4 %, which is improved 13.9 %, 50.6 % and 160.6 % compared with those for pure Ni samples, respectively. The effects of solid solution strengthening, grain refinement strengthening, reinforcement particle strengthening and dislocations behavior of at amorphous/crystalline interface on the combination of high strength and ductility of the composites were discussed. [Display omitted] • Amorphous SiO 2 reinforced Ni matrix composites were fabricated by in-situ pyrolysis of polycarbosilane coated on Ni powders. • Amorphous SiO 2 instead of crystalline SiC formed by the combination of silicon generated in the pyrolysis with oxygen. • The composites exhibit a combination of excellent tensile strength and ductility. [ABSTRACT FROM AUTHOR]

Developing earth-abundant, efficient and durable catalysts toward the hydrogen evolution reaction (HER) is critical for the large-scale deployment of sustainable hydrogen production from renewable energies. Transition metal dichalcogenides (TMDs) are promising candidates for the replacement of precious and state-of-the-art platinum-groups-metals, but their HER performance still needs improvement. Constructing crystalline/amorphous interfaces is effective in terms of creating abundant active sites for boosted catalytic activity. Therefore, in this study, defective crystalline vanadium disulfide/amorphous molybdenum sulfide/reduced graphene oxide (c-VS 2 /a-MoS x /RGO) nanocomposites are fabricated via a combined hydrothermal-plasma method. The HER performance of c-VS 2 /a-MoS x /RGO is optimized by tuning the plasma treatment duration and the amount of precursors, and the corresponding mechanisms were investigated by morphological and elemental analyses. Taking advantage of the high reactivity of low-temperature plasma, the strategy presented in this work is effective in terms of constructing crystalline/amorphous interfaces and introducing multiple defects, which creates abundant active sites and ultimately results in boosted HER performance. The optimal c-20VS 2 /a-40MoS x /RGO catalyst exhibited excellent HER activity (η@100 mA cm−2 = 193 mV and η@500 mA cm−2 = 244 mV) and good stability. This work provides a facile and effective strategy for promoting the HER performance of TMDs and sheds light on rationally designing efficient HER catalysts using earth-abundant elements. [Display omitted] This work describes a combined hydrothermal-plasma method for fabricating defective crystalline vanadium disulfide/amorphous molybdenum sulfide/reduced graphene oxide (c-VS 2 /a-MoS x /RGO) nanocomposites toward hydrogen evolution reaction. The HER activity of c-VS 2 /a-MoS x /RGO can be optimized by adjusting plasma treatment duration and the amount of precursors. Structural and electrochemical characterizations indicate that the optimal c-VS 2 /a-MoS x /RGO catalyst possess abundant active sites, which can be attributed to crystalline/amorphous interface and multiple defects in the heterostructures. The c-VS 2 /a-MoS x /RGO catalysts show excellent activity and good stability for the HER. • This work develops a method for constructing crystalline/amorphous interfaces. • Crystalline/amorphous interfaces are beneficial for boosting HER activity. • The level of lattice defects should be controlled for optimal HER activity. • c-VS 2 /a-MoS x /RGO exhibits boosted HER performance at high current densities. [ABSTRACT FROM AUTHOR]

An amorphous/crystalline metallic composite (A/C-MC) integrates metallic glass with crystalline metals in one system. The amorphous-crystalline interface (ACI) in A/C-MCs under deformation absorbs dislocations and may fundamentally change the dilemma that the strength comes at the expense of the ductility of a material. However, the development of such materials is still at a trial and error stage due to the lack of a clear-cut understanding on how the amorphous component become instable when a dislocation-mediated plasticity flows into the glassy phases. To meet this need, here we focus on gaining the physical insights into the dislocation-ACI reaction in A/C-MCs through atomistic simulations. We have (i) digitally resembled an interface structure close to that in experiments by annealing melted metallic glasses at cooling rates as low as ∼ 104 K/s; (ii) correlated the dislocation absorption events with the activation of shear transformation zones (STZs) in A/C-MCs under a plastic shear; (iii) identified the mechanisms responsible for a continuous dislocation absorption-induced instability in glassy phases; (iv) calibrated a set of constitutive relations, kinetic rules, and model parameters that can be used in an effective temperature concept-based STZ theories at the continuum level; and (v) characterized the local stress states ahead of the instability band and lay the macroscopic-level glass instability criterion on a firm atomistic basis. Our major findings are: (a) there exists a nanoscale structure transition at the ACI when the cooling rate in the atomistic simulations is reduced to an experimentally-comparable level; (b) the number of atoms participating in the STZs exponentially increases with the number of dislocations arriving at the ACI at an early stage of the dislocation-ACI reaction, but is linearly proportional to the number of absorbed dislocations at a later stage; (c) the dislocation absorption-induced instability in metallic glasses occurs through a three-stage process, i.e., the activation of STZs in the region between icosahedral (ICO) clusters, the coalescence of newly formed STZs, and then the breakdown of ICOs; (d) the model parameters in the continuum-level constitutive relations and kinetic rules are found to be sensitive to cooling rates; and (e) the local stress states ahead of the instability band in glassy phases map surprisingly well with the Mohr-Coulomb criterion regardless of the applied stress at the macroscopic level. The gained knowledge may provide a pathway of connecting the atomistic deformation physics of an A/C-MC with its overall mechanical performance, which is currently difficult to achieve in laboratory experiments. [ABSTRACT FROM AUTHOR]

[Display omitted] • a/c-RuCoMo y O x /NF was synthesized by coprecipitation-microwave method. • Microwave time affects the transition from crystalline to amorphous structure. • a/c-interface and electron interaction make a/c-RuCoMo y O x /NF have mighty activity. • The η 10 value of a/c-RuCoMo y O x /NF is 39 and 166 mV for HER and OER. Due to the vast difference in structure and the unique electronic state at the heterointerface, the amorphous/crystalline (a/c) heterostructure exhibits excellent potential in electrocatalysis. However, there are great challenges in constructing the material with ample a/c-heterointerfaces and controllably modulated a/c-heterointerface region through a simple one-step method. Herein, the a/c-RuCoMo y O x /NF (nickel foam) electrocatalyst is synthesized by the coprecipitation-microwave treatment method. Notably, microwave time directly affects the ratio of amorphous region (RuCoMoO x) to crystalline region (CoMoO 4 and CoO). Surprisingly, the a/c-RuCoMo y O x /NF with abundant crystallinity/amorphous heterointerfaces exhibits the ultralow η 10 values of 39 and 166 mV for HER and OER, which are 0.5-fold and 0.63-fold lower than that of Pt/C-NF and RuO 2 -NF benchmarks, respectively. Overall, this work provides a novel idea and convenient method for the construction of amorphous/crystalline heterointerfaces with modulated interface region, and guides the direction for the preparation of superior electrocatalysts by regulating the a/c-heterointerface region. [ABSTRACT FROM AUTHOR]

Abstract WB 2 /CrN multilayer films with thick modulation periods over 50 nm (Λ = 1400, 315, 235, 150, 55 nm) were synthesized by direct-current magnetron sputtering, and the influence of modulation period on microstructure and mechanical properties for the multilayer films was systematically studied. In WB 2 /CrN multilayer films, CrN sublayers present the columnar microstructure. As Λ decreases, the structure of WB 2 sublayers evolves from (110) orientation to (001) orientation to amorphous structure, and critical crystalline thickness for WB 2 sublayers is over 150 nm here. A transition layer, which shows the columnar crystal with size of 10–11 nm high and 2.5–3.5 nm wide caused by the effect of the crystalline interface of the CrN sublayers, is detected in WB 2 sublayers. Additionally, a-BN, WB 2 , WB 2 (N), CrN, Cr 2 N and Cr 2 O 3 phase are formed in the multilayer films. Moreover, film hardness mainly obeys the rule of mixture. The maximum hardness of 31.2 GPa is obtained at Λ = 315 nm due to crystalline WB 2 sublayers with (001) preferred orientation, and amorphous WB 2 sublayers greatly reduce the film hardness to only 22.3–24.3 GPa at Λ ≤ 235 nm. Consequently, the poor hardness leads to the higher wear rates (5.7–7.8 × 10−7 mm3/mN) of multilayer films with Λ ≤ 235 nm compared with those (2.9–3.3 × 10−7 mm3/mN) of other films. However, both the fracture toughness and adhesive strength of the films present an increasing trend with decreasing Λ, resulting from the soft CrN and BN phases and a certain amount of interface. In conclusion, decreasing the critical crystal-thickness of the WB 2 sublayers, controlling the N content in WB 2 sublayers and getting sharp interfaces will play important roles in developing the higher-performance WB 2 /CrN multilayer films. Highlights • WB 2 /CrN multilayer films with different bilayer periods over 50 nm are prepared. • A transition layer with nano-columnar crystal exists between WB 2 and CrN sublayers. • Critical crystalline thickness of WB 2 sublayers is over 150 nm in this work. • Decreasing bilayer period to ≤235 nm causes a reduction in hardness and wear rate. • Multilayer architecture promotes the film toughness and adhesive strength. [ABSTRACT FROM AUTHOR]

Abstract Bismuth magnesium niobate (Bi 3/2 MgNb 3/2 O 7 , BMN) thin films were prepared on bare SiO 2 /HR-Si and Pt/TiO 2 /SiO 2 /HR-Si substrates by using sol-gel spin coating technique followed by rapid thermal annealing process. The influence of the interface on crystalline structure and tunable dielectric properties of the two types of BMN films were investigated. It was found that the BMN films prepared on SiO 2 /Si substrate with a BMN/SiO 2 interface structure had higher orientation and better crystallinity. The deposited BMN thin films with a BMN/SiO 2 interface structure exhibited superior tunability of 52.5%, while it showed a relative small tunability value of the film with BMN/Pt interface structure. It suggests that the interface state between the films and substrates, electric field distribution, and orientation degree are responsible for the impacts on the microstructure and tunable dielectric properties of the BMN thin films. [ABSTRACT FROM AUTHOR]

Abstract Nitrogen containing mesoporous carbon spheres act as a host for Se-S mixed cathode in Li-sulfur batteries. We prepare 50 and 60 wt% of active material (Se-S) containing carbon spheres using a single and two step infusion method individually. Loading of 60 wt% Se-S mixed active material in carbon spheres using a two step infusion method exhibits crystalline nature, whereas single step infusion method yields amorphous product. Interestingly, Se and S involve in the electrochemical reaction with Li. Among the products, 60 wt% Se-S loaded carbon spheres from a two step infusion method effectively suppresses the active material against shuttling and retains about 528 and 387 mAh/g of capacity at C/10 and 1C rate respectively due to the better electronic conductivity and polar nature of ∼5% nitrogen present in the carbon sphere. Further, Se-S@carbon sphere cathode demonstrates better electrochemical performance than S or Se@carbon sphere cathodes. The study deals with the effect of mixed active material loaded carbon spheres and the role of infusion method in improving the electrochemical behaviour of Li-S system both individually and in synergy. Graphical abstract Image 1 Highlights • Influence of infusion method in S-Se mixed cathode property in Li-S is studied. • Mesoporous carbon sphere with ∼5% N is exploited as Se-S cathode scaffold. • Both S and Se participate in the reversible electrochemical reaction with Li. • Better cycleability is observed with 60 wt% Se-S@C obtained from two step method. • Demonstrated 528 mAh/g up to 50 cycles and 273 mAh/g capacity at 2C rate. [ABSTRACT FROM AUTHOR]

Abstract Misfit dislocations at bimetal interfaces play a decisive role in determining various deformation behaviors by carrying the shear sliding, serving as a barrier for dislocation transmission and a source of dislocation nucleation. However, when the interface does not possess the distinct feature of misfit dislocations, the nucleation mechanism of lattice dislocations at the interfaces cannot be simply quantified by previously developed atomistic mechanisms based on characteristic misfit dislocations. Using crystalline/crystalline interfaces with a large lattice mismatch and crystalline/amorphous interfaces without local symmetry as prototypes, we show for the first time that the dislocation nucleation at such interfaces is attributable to the localized strain heterogeneities by modifying the volumetric and shear strain components at the atomic level to mechanically respond to different loadings. Using atomic strain tensor analysis, we found that in-plane localized shearing plays a critical role in the emission of lattice dislocations from interfaces, while the corresponding normal components of the volumetric strain tensor will dominate the character of the nucleated lattice dislocation by modifying the atomic excess volume at the interface to overcome the barrier to dislocation nucleation. Further exploration of various crystalline/amorphous interfaces by varying the chemical composition of the amorphous side indicates that chemical heterogeneity may substantially change the strain heterogeneity by forming a different clustered structure at the interface, resulting in the preferred choice of nucleation sites at the boundary regions that can be defined as nano shear traces (NSTs). These results provide a foundation to investigate the effects of strain and chemical heterogeneities in order to provide a realistic explanation of interface mediated deformation mechanisms and an efficient solution to tune interface dominated plasticity. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

Herein a novel carbon nitride composite with triazine-based crystalline carbon nitride (tri-C 3 N 4 ) vertically aligned on tri- s -traizine-based crystalline carbon nitride (tri- s -tri-C 3 N 4 ) is first proposed for efficient visible light driven (λ > 420 nm) photocatalytic H 2 evolution. The well matched lattice fringes between (002) plane of tri- s -tri-C 3 N 4 and (102) plane of tri-C 3 N 4 characterized by TEM unambiguously demonstrate the successful construction of tight crystalline junction between tri- s -tri-C 3 N 4 and tri-C 3 N 4 . As a result, the crystalline carbon nitride phase junction (tri-/tri- s -tri-C 3 N 4 ) shows a high visible light photocatalytic H 2 evolution activity of 144 μmol/h, which is 30 times higher than that of pristine g-C 3 N 4 . This outstanding photocatalytic H 2 evolution performance could be attributed to the fact that the construction of crystalline tight junction can greatly enhance the transfer and separation efficiency of photoinduced carriers. This study may provide a new way for rational design of carbon nitride heterojunction for gaining high photocatalytic activity. [ABSTRACT FROM AUTHOR]

[Display omitted] • NiCr-based composites with crystalline Cr 3 C 2 and amorphous SiO 2 dual-particles were successfully fabricated. • The composites exhibit a combination of excellent tensile strength and ductility. • The generation and annihilation behavior of dislocations at amorphous/crystalline interface contributes to improve tensile strength and ductility. • Introducing crystalline-amorphous dual-particles into metallic materials can simultaneously improve their strength and ductility. Strength and ductility of structural materials are mutually exclusive in general due to the strength-ductility trade-off. Using in-situ pyrolysis of polycarbosilane in NiCr powder green compacts, we fabricated NiCr-based composites with micro-sized crystalline Cr 3 C 2 and amorphous SiO 2 dual-particles. Tensile tests show that the NiCr-based composites have a combination of high strength and ductility with the yield strength, ultimate tensile strength and ductility as 449 MPa, 838 MPa and 20.5%, respectively. The amorphous SiO 2 and crystalline Cr 3 C 2 particles exhibit plastic deformation and transgranular fracture, respectively, under tensile stress. Besides solid solution strengthening, the generation and annihilation behavior of dislocations at amorphous/crystalline interface and the strain hardening of the ceramic particles by hindering the movement of dislocations mutually contributes to the combination of excellent strength and ductility of our composites. [ABSTRACT FROM AUTHOR]

An intrinsic feature of nearly all internal interfaces in crystalline systems (homo- and hetero-phase) is the presence of disconnections, namely topological line defects constrained to the interface that have both step and dislocation character. We demonstrate that elastic interactions between disconnections strongly affect the morphology and motion of interfaces, allowing for understanding and reconciling diverse key experiments. In particular, these elastic interactions strongly modify equilibrium interface morphologies compared with those solely determined by anisotropic surface energy, and affect the kinetics of migrating interfaces. They are also found to lead to a thermodynamic, first-order, finite-temperature, faceting–defaceting transition. We demonstrate these phenomena through numerical simulations based upon a general, continuum disconnection-based model for interface thermodynamics and kinetics applied to embedded particles/grains, steady-state interface migration geometries, and nominally flat interfaces. [Display omitted] [ABSTRACT FROM AUTHOR]

Diamond-structured grain boundaries (GBs) are important because they have notable effects on the performances of many functional devices. Previous studies have suggested that the most stable structures of some silicon GBs can be obtained by structural reconstruction from some meta-stable GBs explored at 0 K by atomic simulation. While GB reconstruction is possible to enable these meta-stable GBs to exist at elevated temperatures, reports on such behaviors are rare. This work unveiled a non-reported GB reconstruction from two degenerate ground-states of a well-known silicon GB which can be distinguished by an orientational feature of their unit structures. The reconstructing structures were verified stable by density-functional-theory (DFT) simulation. By thermodynamical and kinetical discussion, we have shown that the structural variation of this well-known GB at elevated temperatures is more likely to be dominated by this reconstruction mechanism rather than by transforming to other metastates. Such a reconstruction mechanism allows the whole GB system to be treated as an Ising model with a second-ordered phase transition. By applying harmonic transition state theory, we predicted the possible concentration of the defects induced by reconstruction at elevated temperatures and discussed their effects on the band structure of the GB by DFT simulation. An explanation was made on the cause of the difference between the phase transition behavior of this silicon GB and that of a reported copper GB. Our research made new insights into understanding the behavior of reconstructing interfaces in covalent-bonded crystalline materials. [Display omitted] [ABSTRACT FROM AUTHOR]

The large-area Cu/SS ribbed plate is very significant for the fusion engineering but is difficult to produce by regular cold or hot processing. This thesis takes Cu-alloy plate and 316L SS ribbed plate as materials and adopts a new form of charging to carry out the deepened study and optimization of the supporting formwork from perspectives of design, filling scheme and welding parameters. It prepares a large-area dual-metal ribbed plate by the explosive weld and conducts the shear strength test, metallographic observation, scanning electron microscopy and micro-hardness test of the weld interface. The result indicates that most weld interface is the wavy metallurgical bond interface of the direct transition of Cu/SS but “coronary” vortexes containing metallic oxide exist on both sides of the crest. Crystalline grains near the bond interface are lengthened and thinned, the micro-hardness is increased significantly and the bond strength of interface is even greater than that of copper. [ABSTRACT FROM AUTHOR]

Molybdenum substitution by chromium in ZrCr 1-x NiMo x alloys produces the segregation of Zr x Ni y phases, ZrCr 2 and ZrMo 2 Laves phases as it was stated in Part I of this paper. In order to study the contribution of these phases in ZrCr 1-x NiMo x alloys performance, secondary Zr 9 Ni 11 and Zr 7 Ni 10 , together with ZrCr 2 and ZrMo 2 Laves phases were synthesized and their crystalline structures determined with XRD patterns. Zr 7 Ni 10 exhibits an orthorhombic structure, whereas Zr 9 Ni 11 depicts a tetragonal structure. ZrCr 2 presents a hexagonal structure (C14), while ZrMo 2 depicts a cubic structure (C15). ZrCr 2 shows zero discharge capacities, while ZrMo 2 exhibits a first capacity value of 245 mAh g −1 . Zr 9 Ni 11 and Zr 7 Ni 10 phases exhibit maximum discharge capacities of 119 and 157 mAh g −1 , respectively. Theoretical results show that the hydride stability for ZrCr 2 is larger than that for ZrMo 2 . However, the great hydrogen storage capacity yields a slower desorption kinetics since it requires a considerable de-hydrogenation energy. The opposite effect is observed for the proposed hexagonal structure ZrMo 2 . The 100% charge of the alloys shows different results for the hydrogen evolution reaction. Zr 7 Ni 10 phase depicts a better performance since the required potentials are lower than −1.05 V. There is a change in the rate determining step ( rds) from a chemical recombination of surface hydrogen (Tafel pathway) in Zr 7 Ni 10 to a fast first electron transfer (Volmer step) for Zr 9 Ni 11 . Thus, the rds is strongly affected by the type of secondary phase dominant in each sample, being Zr 7 Ni 10 the most favorable. [ABSTRACT FROM AUTHOR]

We have studied the formation of epitaxial ferromagnetic/ferrimagnetic MnGa(0 0 1)/Mn 4 N(0 0 1) heterostructures by using spin polarized first principles calculations. In particular, we have analyzed the stability of the surface and interface as function of the N content. Since the Mn 4 N(0 0 1) has two stable surface terminations with a (1 × 1) periodicity, we have used them as substrates to grow MnGa. The interface formation energy formalism has been applied to describe the stability of all proposed models. Our calculations show that Mn at the interface is energetically favorable. Moreover, stability of the MnGa surface has a direct nitrogen dependence. Specifically, without extra N, the Ga-terminated surface is stable in the whole range of chemical potential for both substrates. Once N is added to the surface, the MnN-terminated surface becomes stable in both substrates for different ranges of chemical potential. Although MnGa and Mn 4 N are not antiferromagnetic materials, they form a local antiferromagnetic-like arrangement at the interface. This thermodynamically stable system could have potential applications in the construction of new generation spintronic devices. [ABSTRACT FROM AUTHOR]

Single crystalline homoepitaxial Nb doped TiO 2 (TiO 2 :Nb) films were deposited on rutile TiO 2 (r-TiO 2 ) (001) substrates by metal organic chemical vapor deposition (MOCVD). Effect of Nb doping on structural and electrical properties of the films were studied. The maximum Hall mobility of the obtained films reached as high as 14.0 cm 2 V −1 s −1 and the lowest resistivity of the films was 1.9 × 10 −1 Ω cm which was 7 orders of magnitude lower than that of pristine r-TiO 2 . The obtained films were single crystalline r-TiO 2 epitaxially grown along the (001) orientation. The relationship between the structural and electrical properties was discussed. TiO 2 :Nb films with high mobilities may have many potential applications in the field of transparent electronic devices. [ABSTRACT FROM AUTHOR]

In this study, the influence of crystalline orientation on the plasticity of metallic amorphous-crystalline interface (ACI) has been investigated in a model system of crystalline Cu-amorphous CuZr multilayers by molecular dynamics simulations. It is found that the ACIs with various crystalline orientations all show similar structure with a gradual transition from crystalline to amorphous. As a result, the energy of ACIs shows only a weak dependence on the crystalline orientation. Additionally, the ACI shows no stress concentration or area of high energy than the rest of the materials. Those findings are in contrast to other types of planar defects such as grain boundaries or free surfaces. However, the strength and the yielding behavior vary significantly among the different amorphus-crystalline (A-C) multilayers. Specifically, it is found that the yielding mechanism, e.g., through dislocation nucleation in the crystalline Cu or through shear localization in the amorphous CuZr layer, is mainly determined by the crystalline orientation. What is more, the simulations on ACIs with polycrystalline Cu suggest that the plasticity of A-C multilayers strongly depends on the texture orientation of the columnar grains in the Cu layer, which can be used to explain some of the experimental observations on similar materials. [ABSTRACT FROM AUTHOR]

Photo-carrier transport process and mobility in the different phases including crystalline and isotropic phases of a liquid crystalline photoconductor material from the 2-phenylnaphthalene derivative, 2-(4’-octylphenyl)-6-dodecyloxynaphthalene (8-PNP-O12) was re-investigated as function of electric field and temperature by using time of flight (TOF) transient photocurrent technique. Charge carrier transport is discussed in different phases from the measurement of the transient photocurrent. In the mesophases, experimental data, in agreement with previous results, highlight electronic and ionic conductions. Moreover, were revealed electronic transport in isotropic phase of a liquid crystalline material and crystalline phase of this compound. [ABSTRACT FROM AUTHOR]

The pitting corrosion resistance has been evaluated for a powder-processed Al-Cr-Mn-Co-Zr alloy which contains ≈35% by volume of an icosahedral quasi-crystalline phase and a little Al 9 Co 2 in an Al matrix. ASTM standard salt fog exposure tests show that the alloy exhibits far lower corrosion pit densities and depths than commercial high-strength aerospace Al alloys under the same conditions. Electron microscopy data show that the salt fog exposure leads to the selective oxidation of the face-centered cubic Al matrix around the other phases, and to the development of a porous outer oxide scale. [ABSTRACT FROM AUTHOR]

The interactions between precipitated calcium carbonate (PCC) and sterically stabilized nanocrystalline cellulose (SNCC) have been studied. SNCC is produced by periodate oxidation of cellulose fibres and consists of a crystalline cellulose region from which dialdehyde modified cellulose chains are protruding from both ends. The morphology of SNCC can be controlled by the degree of oxidation, which depends on the amount of periodate and the reaction time. In this study, three SNCCs with different reaction times were prepared and their interactions with PCC particles were examined. These SNCC particles have similar diameters (5–10 nm) and their length is reduced with increasing reaction time, whereas the length of the protruding chains is increased. Adsorption isotherms of three SNCCs and dialdehyde modified cellulose (DAMC) on PCC particles were determined. It was found that DAMC had a higher affinity than SNCCs, and the affinity of SNCC increased with reaction time. This indicates that DAMC chains adsorb stronger than the crystalline region of SNCC on PCC. The PCC flocculation induced by three SNCCs was monitored by photometric dispersion analysis, which showed that SNCC particles could bridge PCC to induce flocculation at low dosages (above 1 mg/g). SNCC induced the maximum flocculation when its fractional coverage is above 50%, implying that PCC particles coated by SNCC continue to flocculate, as observed experimentally. Further addition of SNCC to PCC suspensions results in slower flocculation rates and smaller floc sizes. [ABSTRACT FROM AUTHOR]

• Innovative passivating contact using quantum well at poly-Si/c-Si interface. • Efficacy of quantum well on large-area TOPCon device is discussed. • The quantum well improves the V oc by 20 mV. • The quantum-well device achieves an efficiency of 23.91%. Polysilicon/crystalline silicon (poly-Si/c-Si) passivating contact is attracting attention as a promising passivation technology for c-Si solar cells. Recently, we have proposed a quantum-well passivating contact (QWPC) that uses a quantum-well at the poly-Si/c-Si interface to suppress recombination, such as Auger and/or Shockley-Read-Hall recombination, due to deep dopant-diffusion problems from poly-Si into the c-Si absorber and, as a result, promote the passivation quality. Herein, we demonstrate the effectiveness of the QWPC in a large area (272.13 cm2) of c-Si photovoltaic devices. A reference device, featuring a front boron diffusion emitter and normal rear poly-Si/c-Si passivating contact without QWPC, achieves a certified 22.99% conversion efficiency. The QWPC significantly reduces recombination losses within the device, as demonstrated by bias external quantum efficiency and dark I-V characteristics. The QWPC improves the open-circuit voltage (V oc) by 20 mV. An antireflection magnesium fluoride coating applied at the front along with the QWPC improves the short-circuit current density by 1.27 mA/cm2. The QWPC device achieves a conversion efficiency of 23.91%. The QWPC demonstrates an innovative passivating contact for promoting c-Si solar cell performance. [ABSTRACT FROM AUTHOR]

GdPO 4 is a promising thermal barrier coating (TBC) candidate owing to its excellent resistance to calcium-magnesium-alumina-silicate (CMAS) and molten salt corrosion. In this study, the corrosion behavior of GdPO 4 in CMAS + molten salt (CN) was investigated and compared with that in CMAS. At 1200 and 1250 °C, interface reaction layers rapidly formed on both the CN and CMAS attacked GdPO 4 pellets, and many crystalline products were generated in the melts. This effectively increased the melt viscosity and suppressed its penetration. As compared to CMAS, CN was more aggressive to GdPO 4 at 1200 °C but less at 1250 °C. [Display omitted] • CMAS + NaVO 3 (CN) and CMAS corrosion behavior of GdPO 4 was studied and compared. • The interface reaction layers on the CN and CMAS attacked GdPO 4 pellets had different phase compositions. • The reactive crystalline products in CN and CMAS melts on GdPO 4 pellets were different. • The formed crystalline products and interface reaction layers increased the melt viscosity and inhibited melt penetration. • As compared to CMAS, CN was more aggressive to GdPO 4 at 1200 ℃ but less at 1250 ℃. [ABSTRACT FROM AUTHOR]

[Display omitted] The CSL/DSCL model for interfaces in crystalline materials offers a unified framework to study interface dislocations in phase boundaries and disconnections in grain boundaries. The model relies on the existence of a coincidence relation between the two lattices that meet at an interface. The model's ability to quantitatively predict the thermodynamics and kinetics of interfaces has been demonstrated for a limited set of symmetric tilt grain boundaries (STGBs) in cubic materials and twin boundaries. However, the lack of a general framework of interface defects prevents its applicability to arbitrary rational boundaries. In this paper, we present a mathematical framework based on the Smith normal form (SNF) for integer matrices to study the bicrystallography of rational phase and grain boundaries. One of the main results of the paper is a constructive proof of the invariance of the coincident site lattice (CSL) under discrete relative displacements of the parent lattices (of possibly different kind) by a displacement shift complete lattice (DSCL) vector. In addition, we obtain necessary and sufficient conditions on two lattices, related by not only rotations but also lattice distortions, for the existence of a coincidence relation. We first apply these results to explore coincidence relations in arbitrary phase boundaries, and study interface dislocations. In particular, we demonstrate the framework for a phase boundary formed by a strained hexagonal lattice and a square lattice. As a second application, we show how to enumerate all possible (geometric) disconnection modes in arbitrary rational grain boundaries, including glide and non-glide modes in both STGBs and asymmetric-tilt grain boundaries (ATGBs). The constructive nature of the framework lends itself to an algorithmic implementation based exclusively on integer matrix algebra to construct all interfaces that admit CSLs up to a prescribed size, and determine disconnection modes in grain boundaries. We demonstrate the use of SNF bicrystallography on selected bicrystal misorientation axes/angles in face-centered cubic (fcc), body-centered cubic (bcc), and hexagonal (hex) lattices. [ABSTRACT FROM AUTHOR]

[Display omitted] Since the nuclear waste releases heat during the decay process, the mechanical behaviors of granites adjacent to the nuclear waste repository are inevitably impacted by the discrepancies in the thermal expansion characteristics of composite minerals. In this study, a mesostructure-based model (MSBM) was first proposed to characterize the thermal behaviors of varying minerals and cementation interfaces with consideration of the aperture-dependent weakening effects of pre-existing micro-cracks on mineral properties. Based on the MSBM, nine sets of numerical models with different mineral compositions were generated to explore the relationship between the mineral composition and the macro mechanical behaviors of granite at the temperatures of 25–250 °C. The meso -mechanisms behind the varied macro mechanical behaviors were comprehensively analyzed. The results indicate that the macro mechanical properties, i.e., the uniaxial compressive stress (UCS) and elastic modulus (E) are dependent on the combined effects of the different thermal expansion characteristics of minerals and the different thermoelastic behaviors of the crystalline interfaces, especially the quartz-biotite and quartz-feldspar mineral boundaries. Finally, an evaluation system aiming to quantify the effects of mineral composition and temperature on the mechanical behaviors of granite was proposed. Principal minerals such as quartz and feldspar strongly influence the UCS and E of the rock at different temperatures, and the influence of feldspar on UCS becomes more pronounced with increasing the temperature. Biotite has little influence on the change in elastic modulus with temperature, while the contribution of biotite to UCS varies with the temperature. [ABSTRACT FROM AUTHOR]

In the rapidly developing modern industrial fields, the materials used are often required to have simultaneously high strength and high electrical conductivity. However, these two properties often conflict and cannot be met at the same time. In the present study, we developed the Cu/Cu–Zr–Al bulk metallic glass (BMG) composites which exhibited simultaneously high strength and high electrical conductivity, as well as large plasticity. The BMG composites were fabricated by using spark plasma sintering crystalline Cu-coated Cu–Zr–Al metallic glass composite powders. The effect of particle size of the Cu–Zr–Al metallic glass powders on mechanical properties and electrical properties of the BMG composites was investigated systematically. Microstructure of contact interfaces between crystalline Cu and Cu–Zr–Al metallic glass was also characterized and discussed. This study is expected to provide an effective technical approach for the development of new high strength and high conductivity materials. [Display omitted] • The BMG composites with simultaneously high strength and high conductivity were developed. •The composites were fabricated by sintering Cu-coated Cu–Zr–Al glassy composite powders. •Effect of particle size on mechanical and electrical properties was investigated systematically. •Optimum Cu–Zr–Al metallic glass particle size of the BMG composites with both high strength and high conductivity was below 50 μm. •Good bonding between crystal and glassy is responsible for excellent comprehensive properties. [ABSTRACT FROM AUTHOR]

Amorphous films deposited by pulsed laser deposition from a crystalline Li 2 PO 2 N target in a N 2 ambient atmosphere (LiPON-PLD) have been examined as an approach to reduce the charge-transfer resistance at the electrode-solid electrolyte interface. Despite the relatively low ionic conductivity of ca. 1.5 × 10 −8 S cm −1 at 25 °C, the amorphous LiPON-PLD films deposited between a LiMn 1.485 Ni 0.45 Cr 0.05 O 4 (LNM) cathode and LiPON electrolyte resulted in sharply improved electrochemical performance in terms of charge-transfer resistance and CV profiles. Cells without a LiPON-PLD film had a charge-transfer resistance of 4470 Ω-cm 2 compared to 760 and 960 Ω-cm 2 for the sample with 17 nm and 31 nm thick LiPON-PLD films, respectively. The LiPON-PLD amorphous films show no evidence of the continuous planar P N P N- backbone characteristic of the crystalline target material, but compared with LiPON prepared from radio frequency magnetron sputtering with Li 3 PO 4 in a N 2 atmosphere, the LiPON-PLD films were composed of a higher amount of triply coordinated P − N < P P with relatively lower contributions of P N P. [ABSTRACT FROM AUTHOR]

Nanocrystalline TiO 2 catalysts with different anatase/rutile ratios have been successfully prepared using a single-step solution combustion synthesis (SCS). The synthesized powders were characterized using XRD, Raman, XPS, FT-IR, SEM, TEM, BET and UV–vis DRS. The effects of urea-to-nitrate molar ratio on the phase structure, morphology and photocatalytic activity of the TiO 2 powders were investigated. Results show that the urea contents play an important role in controlling the crystal structure of the samples. Specifically, well-dispersed anatase/rutile TiO 2 nanocomposites (anatase 66.2%, rutile 33.8%) with excellent photocatalytic activity can be obtained when the molar ratio of urea-to-nitrate is 0.50. The synergistic effect between the anatase and rutile is responsible for the enhanced performance of this material. Moreover, a thermodynamic calculation was performed to interpret the phase transformation mechanism during the combustion process. [ABSTRACT FROM AUTHOR]

This paper reviews and examines interatomic potentials or force fields for molecular dynamics (MD) simulation of crystalline silica. The investigated potentials are the BKS, Pedone, Munetoh, TTAM, and CHIK. The calculated values of the lattice constants, density, radial and bond-angle distribution functions, equations of state, and phase transitions using different potentials are compared to experimental values for polymorphs of silica: quartz, cristobalite, coesite, and stishovite. Simulation results with the BKS potential accurately predict the experimental measurements to within 2%, and converge within a reasonable timeframe on an average workstation. The Pedone potential, also parameterized for other metallic oxides, computationally is slightly more expensive and is not as accurate. The simulations with both the CHIK and TTAM potentials are less accurate than with the BKS potential for modeling silica over the entire range of the phase diagram. The simulations with the Munetoh potential are by far the cheapest in terms of the modest computational requirements, but unsuitable for modeling crystalline silica. It could not produce the nature of the α–β and I–II phase transitions in quartz or the equation of state for stishovite silica, and the predicted structural properties sometimes differ from experimental values by more than 10%. [ABSTRACT FROM AUTHOR]

For industrial high-purity hydrogen production, it is essential to develop low-cost, earth-abundant, highly-efficient, and stable electrocatalysts which deliver high current density (j) at low overpotential (η) for oxygen evolution reaction (OER). Herein, we report an active mesoporous Ni 2 P @ FePO x H y pre-electrocatalyst, which delivers high j = 1 A cm−2 at η = 360 mV in 1 M KOH with long-term durability (12 days), fulfilling all the desirable commercial criteria for OER. The electrocatalyst shows abundant interfaces between crystalline metal phosphide and amorphous phosphorus-doped metal-oxide, improving charge transfer capability and providing access to rich electroactive sites. Combined with an excellent non-noble metal-based HER catalyst, we achieve commercially required j = 500/1000 mA cm−2 at 1.65/1.715 V for full water-splitting with excellent stability in highly corrosive alkaline environment (30% KOH). The alkaline-anion-exchange-membrane water-electrolyzer (AAEMWE) fabricated for commercial viability exhibits high j of 1 A cm−2 at 1.84 V with long-term durability as an economical hydrogen production method, outperforming the state-of-the-art Pt/C – IrO 2 catalyst. [Display omitted] • Noble-metal free catalysts for oxygen evolution reactions are investigated. • Crystalline (Ni 2 P) and amorphous (FePO x H y) phases in Ni 2 P @ FePO x H y catalyst provide more electrocatalytic active sites. • The Ni 2 P @ FePO x H y catalyst shows excellent AAEMWE cell performance with a low overpotential and good stability. • The Ni 2 P @ FePO x H y catalyst exhibits a low overpotential of 360 mV for OER to deliver a high current density of 1 A cm−2. [ABSTRACT FROM AUTHOR]

[Display omitted] • Innovative passivating contact using poly-Si/quantum well/c-Si contact. • Quantum well suppresses dopant diffusion from the poly-Si layer into c-Si bulk. • Excellent passivation quality achieved with iV oc of 742 mV and J o of 1.1 fA/cm2. Herein, we propose a quantum well comprising a stack of SiO x /nanocrystalline silicon (nc-Si)/SiO x layers between a polycrystalline silicon (poly-Si) layer and a crystalline silicon wafer (c-Si) for enhancing the passivation quality through the poly-Si/c-Si passivating contact for c-Si solar cells. A large number of dopants can diffuse deeply into c-Si from a heavily doped poly-Si layer during high-temperature annealing, reducing the surface passivation quality. The quantum well with the double SiO x layer plays a significant role as a double barrier, thus suppressing this. The formation of the nc-Si phase sandwiched between the SiO x layers can support carrier transport, i.e., the tunnelling of carriers through the SiO x layers for collection. Moreover, a highly doped poly-Si/quantum well/c-Si contact exhibits considerable improvement in the passivation quality, achieving a high iV oc of 742 mV and low J o of 1.1 fA/cm2, compared with a reference poly-Si/c-Si passivating contact (iV oc = 707 mV, J o = 32.5 fA/cm2). The results indicate the effectiveness of the innovative passivating contact concept and pave the way for further improvements in the performance of c-Si solar cells. [ABSTRACT FROM AUTHOR]

Abstract: High-resolution electron microscopy was used to research the age-hardening behaviors in 6005A alloy and the microstructural characterizations of precipitates. It was found that β″, β′ and Q′ precipitates had 12 orientation variants, respectively, the smaller size and a high-density β′′ precipitates existed in alloy for a long time, which played a very important role in controlling an anti-overaged softening behavior in 6005A alloy. Further, by the crystallographic interface and morphology analysis, a main reason was that a 2-dimensions coherency strain-field not only had the high-density β′′ precipitates become the biggest obstacle of dislocations movement, but also made them transform into β′ and Q′ precipitates with more difficulty. Moreover, it was also found that β′ and Q′ precipitates had weaker relatively strain-fields, the larger size and a lower density, which were largely associated with the reduction in hardness that occurred upon overaging. Further, the strengthening of precipitates on alloys could be summarized as: β″>Q′>β′. Based on the structural information, the quantitative Moiré fringes analytical technique was also used to verify the lattice parameters and orientation of precipitates. [Copyright &y& Elsevier]

Abstract: The influences of solvent solubility and solution aging on the crystallization of poly(3-hexylthiophene) (P3HT) films were investigated. The solubility difference rather than the evaporation rate of solvent determined the final morphology and crystallinity of film. Marginal solvents (toluene and xylene) with large solubility difference caused crystalline aggregations in solutions during the aging process and then densely stacked network-like structures in solid films. Few crystalline aggregates in good solvent chloroform resulted in a thin layer of fibrillar crystals on the substrate, while dot-like crystals deposited on the substrate from good solvent chlorobenzene since no crystalline aggregates formed in the solution. [Copyright &y& Elsevier]

Abstract: Well-aligned SnO2 nanorod arrays were grown directly on a single-crystalline Si, conductive and quartz glass substrates by thermal evaporation of a mixture of stannous chloride dihydrate (SnCl2·2H2O) and anhydrous zinc chloride (ZnCl2) powders at 600°C in air. The SnO2 nanorod is a single crystalline with a tetragonal structure and grows along the [001] direction. A single-layer SnO2 nanoparticle film is first formed via the vapor–solid (VS) process based on the decentralization function of ZnCl2 vapor in the reaction chamber. The SnO2 nanoparticles served as seeds, and grew into nanorod arrays via the VS process. The density of the nanorods can be changed by adjusting the weight ratio of ZnCl2 to SnCl2·2H2O in the mixture. The field emission properties of the SnO2 nanorod arrays were measured, and exhibited a turn-on field of 1.67Vμm−1 and a field-enhancement factor of 2866. Moreover, this low-temperature VS growing process may be employed for the synthesis of highly oriented nanorod arrays of other oxides, and provides opportunities for both fundamental research and technological applications. [Copyright &y& Elsevier]

Abstract: Diffusion in solids is a well-known phenomenon that has many consequences in technology and material science. Modelling of diffusion-controlled processes requires both a reliable theory of diffusion and reliable kinetic coefficients, as well as other thermodynamic data. Often the classical Darken theory, valid for stress-free systems with ideal vacancy source and sink activity, is generalized to multicomponent systems with ideal vacancy source and sink activity. Nazarov and Gurov presented a theory for stress-free systems with no vacancy source and sink activity. Recently we published a general theory of diffusion that accounted for the role of non-ideal vacancy source and sink activity, as well as the stress state. Since diffusion theories are tested and diffusion coefficients measured usually on diffusion couples, this paper presents evolution equations based on that general theory for a diffusion couple. In the limit, the equations of the Darken theory and the Nazarov and Gurov theory are valid for ideal vacancy source and sink activity and no vacancy source and sink activity, respectively. Simulations for binary and ternary diffusion couples demonstrate the influence of the vacancy source and sink activity and the stress state on evolution of site fraction profiles of components and vacancies, and on the Kirkendall effect. [Copyright &y& Elsevier]

Abstract: The problem of a screw dislocation interacting with a core–shell nanowire (coated nanowire) containing interface effects (interface stresses) is first investigated. The interaction energy and the interaction force are calculated. The interaction force and the equilibrium position of the dislocation are examined for variable parameters (interface stress and material mismatch). The influence of the core–shell nanowire and the interface stresses on the interaction between two screw dislocations is also considered. The results show that the impact of the interface stresses on the motion and the equilibrium position of the dislocation near the core–shell nanowire is very significant when the radius of the nanowire is reduced to nanometer scale. [Copyright &y& Elsevier]

Abstract: Three thermostable neutral cellulases from Melanocarpus albomyces, a 20-kDa endoglucanase (Cel45A), a 50-kDa endoglucanase (Cel7A), and a 50-kDa cellobiohydrolase (Cel7B) heterologously produced in a recombinant Trichoderma reesei were purified and studied in hydrolysis (50°C, pH 6.0) of crystalline and amorphous cellulose. To improve their efficiency, M. albomyces cellulases naturally harboring no cellulose-binding module (CBM) were genetically modified to carry the CBM of T. reesei CBHI/Cel7A, and were studied under similar experimental conditions. Hydrolysis performance and product profiles were used to evaluate hydrolytic features of the investigated enzymes. Each cellulase proved to be active against the tested substrates; the cellobiohydrolase Cel7B had greater activity than the endoglucanases Cel45A and Cel7A against crystalline cellulose, whereas in the case of amorphous substrate the order was reversed. Evidence of synergism was observed when mixtures of the novel enzymes were applied in a constant total protein dosage. Presence of the CBM improved the hydrolytic potential of each enzyme in all experimental configurations; it had a greater effect on the endoglucanases Cel45A and Cel7A than the cellobiohydrolase Cel7B, especially against crystalline substrate. The novel cellobiohydrolase performed comparably to the major cellobiohydrolase of T. reesei (CBHI/Cel7A) under the applied experimental conditions. [Copyright &y& Elsevier]

[Display omitted] • Amorphous Ni-Co-S/crystalline MnS is confined on/in hollow carbon nanospheres. • The formation mechanism of the triple-shelled hollow nanostructure is studied. • The optimized electrode shows a high capacity of 1093C g−1 at 1 A g−1. • The capacitance retention of all-solid-state device is 87.7% after 10,000 cycles. Designing novel electrode materials with controlled structure and composition remains a great challenge for high-performance supercapacitors. Here, a triple-shelled hollow nanostructure has been successfully designed and constructed by confining amorphous Ni-Co-S/crystalline MnS on the inner walls and the outer surfaces of hollow carbon nanospheres. The triple-shelled hollow nanostructure can improve the electrochemically active surface areas, accelerate the transport of electrons/ions, and accommodate the volume change during cycling. Additionally, the interlayer (the porous hollow carbon nanospheres) can support each other for enhanced mechanical stability and improve the electrical conductivity of the electrode. More importantly, amorphous Ni-Co-S facilitates diffusion and redox reaction of OH–, while the crystalline MnS offers fast electrons transport and mechanical stability. Meanwhile, the amorphous/crystalline interface can improve charge storage. Benefiting from the structural and compositional advantages, the prepared electrode delivers a high specific capacity (1093C g−1 at 1 A g−1) and outstanding cyclic stability (capacity retention ratio of 90.4% at 10 A g−1 after 5000 cycles). The corresponding all-solid-state hybrid supercapacitor achieves long cycle life and high energy density. [ABSTRACT FROM AUTHOR]

• Tensile behaviors of triple-phase Ti/Ni nanolaminates are studied by MD method. • Acceptable plastic properties are obtained with proper amorphous layer spacing. • Co-deformation of different phases dominate plastic deformation. • ACIs and CCIs impede plastic deformation carriers penetrating through interfaces. • ACIs and CCIs connect plastic deformation carriers in different phases. [Display omitted] Superior properties of Ti/Ni nanolaminates prompt researchers to comprehend their mechanical behaviors deeply. Lacking investigations at several nanometers range limits their applications in high-precision fields, as the amorphous phase can be formed at the junction regions. By using the molecular dynamics method, three models are chosen to investigate the role of the amorphous layer and different interfaces in triple-phase Ti/Ni nanolaminates during the tensile process. The results demonstrate that mechanical performances of triple-phase nanolaminates are closely related to the fraction of crystalline and amorphous phases. Strength of the nanolaminates decreases with increasing amorphous layer spacing (d). However, acceptable plastic properties can be achieved when amorphous layer spacing satisfies d ≤ 3.91 nm. Microstructure evolution analysis reveals different plastic deformation carriers nucleate and propagate in crystalline and amorphous layers, which contains grain reorientation and basal dislocation propagation in Ti layer, partial dislocations propagation in Ni layer, formation and expansion of shear transformation zones in the amorphous layer. Plastic co-deformation of dissimilar phases dominates the plastic deformation of triple-phase nanolaminates. Crystalline/crystalline interfaces (CCIs) and amorphous/crystalline interfaces (ACIs) also play vital roles in plastic deformations. CCIs impede and absorb the grain boundaries moving toward the interfaces and then act as dislocation sources. ACIs accommodate local deformation at the interfacial regions, and are preferred sites for different plastic deformation carries nucleation. ACIs and CCIs can also connect the plastic deformation carries in different phases, which improves the overall plasticity of triple-phase nanolaminates. The insights obtained in this work can promote the design and application of advanced Ti/Ni nanolaminated materials. [ABSTRACT FROM AUTHOR]

Abstract: Molecular dynamics (MD) simulations are used to model dislocation nucleation at or near symmetric tilt bicrystal copper interfaces with 〈100〉 or 〈110〉 misorientation axes. MD simulations indicate that orientation of the opposing lattice regions and the presence of certain structural units are two critical attributes of the interface structure that affect the stress required for dislocation nucleation. Boundaries that contain the E structural unit are found to emit dislocations at comparatively low tensile stress magnitudes. A simple model is proposed to illustrate the impact of interfacial porosity and stresses acting on the slip-plane in non-glide directions on tensile interface strength. Accounting for interfacial porosity through an average measure is found to be sufficient to model the tensile strength of boundaries with a 〈100〉 misorientation axis and many boundaries with a 〈110〉 misorientation axis. [Copyright &y& Elsevier]

Abstract: The chemical potential of a curved interface contains a term that is proportional to the product of the interface curvature and the interface stiffness. In crystalline materials, the interface stiffness is a tensor. This paper examines several basic issues related to the properties of the interface stiffness, especially the determination of the interface stiffness in particular directions (i.e. the commonly used scalar form of the interface stiffness). Of the five parameters that describe an arbitrary grain boundary, only those describing the inclination are crucial for the scalar stiffness. We also examine the influence of crystal symmetry on the stiffness tensor for both free surfaces and grain boundaries. This results in substantial simplifications for cases in which interfaces possess mirror or rotational symmetries. An efficient method for determining the interface stiffness tensor using atomistic simulations is proposed. [Copyright &y& Elsevier]

Abstract: Degree of crosslinking in silane-water crosslinked ethylene–octene copolymer and its blends with low-density polyethylene was investigated, using three different techniques: the conventional gel content determination, solvent uptake factor method and infrared analysis. The results from those techniques show a similar trend in which the degree of crosslinking increases with increase of crosslinking time, and decreases with increase of crystalline portion in the materials. The measurement of gel content, although it is a direct way to yield results on degree of crosslinking, is time consuming and uses a large amount of solvent for extraction. Also, good care must be taken when analysing the gel content of samples with low degree of crosslinking. Analysis of FTIR data has shown potential for the determination of crosslink variations in the silane crosslinked materials and gives meaningful information on the progress of the silane-water crosslinking reaction. [Copyright &y& Elsevier]

Abstract: Unit cell volumes of intermetallic compounds have been calculated using reported volume size factors. An equation to calculate unit cell volume for intermetallics of any crystalline structure was derived from previously reported expressions for L12 and B2 compounds. Average error for 122 analyzed compounds was 3.16%. Errors ranged from 0.00 to 14.01%. Factors that could influence the error value, such as order, structure type, solid solubility, and type of elements forming the compound were evaluated. A combination of solid solubility and type of elements forming the compounds seem to be the most relevant factors influencing the error value. [Copyright &y& Elsevier]