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Simultaneously enhancing the strength, plasticity, and toughness of metal materials has been a prominent research objective. In this study, the precipitation of nano-scale vanadium carbide particles at a lower tempering temperature is controlled to achieve three key benefits: reducing lattice distortion in bainitic ferrite, strengthening through precipitation, and enhancing the toughness of bainitic ferrite, while also maintaining the content and stability of retained austenite. The adopted procedure increases the comprehensive mechanical properties of steel by 17%. In particular, the room-temperature impact toughness is increased by 41%. This comprehensive microstructure optimization endows bainitic steel with an excellent combination of mechanical properties. [ABSTRACT FROM AUTHOR]

Near‐infrared (NIR) phosphors have been widely used in biomedical applications based on their deep tissue penetration. However, the lack of blue‐pumped NIR phosphors with emission ranges beyond 1000 nm has greatly limited the development of NIR phosphor‐converted light‐emitting diodes (pc‐LEDs). Herein, a facile way to boost the luminescence efficiency and thermal stability by introducing the promoters of Ce3+ and Na+ into Nd3+‐doped SrS NIR phosphor is demonstrated, thus achieving light emitting at 850–1500 nm with a peak wavelength of ≈1070 nm. Through sensitization by the allowed 4f → 5d transition of Ce3+, the SrS: Nd3+ phosphors are excitable by using a commercial blue LED, attributing to the effective energy transfer between Nd3+ and Ce3+. Besides, the structural analysis and density functional theory calculations reveal the lattice distortion mechanism and geometry of doping ions contributed to the weakened thermal quenching effect and the increasing of internal quantum efficiency. The optimized NIR phosphor luminescence intensity remains at 91.8% of the initial intensity at 393 K, and the internal quantum efficiency increases to 42.8% from 31.7% of the sample without Na+ doping. The present exploration of Nd3+‐doped NIR phosphors will provide a reference for designing NIR pc‐LEDs with enhanced properties. [ABSTRACT FROM AUTHOR]

High Q (Hf1−xSnx)O2 ceramics were prepared via a standard solid‐state reaction route, and the microwave dielectric characteristics were investigated systematically together with the structure evolution. With increasing x, the structure changed from HfO2 (monoclinic in space group P21/c, x = 0 and 0.03) to Hf0.77Sn0.23O2 (orthorhombic in space group Pbcn, x = 0.23), while the two‐phase structure: HfO2 major phase and Hf0.77Sn0.23O2 secondary phase, was determined for x = 0.05–0.21, and Hf0.77Sn0.23O2 major phase combined with SnO2 tetragonal secondary phase in space group P42/mnm was confirmed for x = 0.30–0.40. The Qf value was significantly increased from 24,500 to 167,650 GHz by Sn‐substitution, and the best combination of microwave dielectric characteristics was obtained in Hf0.77Sn0.23O2 ceramics: εr = 17.2, Qf = 167 650 GHz at 9.6 GHz and 230 710 GHz at 26.1 GHz, and τf = −52.6 ppm/°C. The dielectric loss was deeply linked with the structure stability and lattice‐distortion. Also, the phase composition, the bond strength, as well as the degree of covalency, had a tight connection with dielectric loss. The present ceramics were expected to be the promising candidates as low‐εr microwave dielectric ceramics. [ABSTRACT FROM AUTHOR]

High entropy alloys (HEAs) are promising electromagnetic wave absorption (EMA) materials due to its designable crystal structure, variable electromagnetic properties, and excellent corrosion resistance. However, the impedance mismatch owing to the high electric and dielectric conductivity severely hinders the application of HEAs in the field of EMA. Herein, the lattice distortion of FeCoNiCu HEA is manipulated accurately by doping and annealing strategies to tailor the EMA properties. Significant lattice distortion is observed in the FeCoNiCuC0.37, which leads to a decrease in the electrical conductivity and the creation of abundant dipoles. Owing to the optimal impedance matching and boosted polarization loss, the FeCoNiCuC0.37 delivers a minimal reflection loss of −65.4 dB accompanied by an effective absorption bandwidth (EAB) of 6.81 GHz. After annealing at 200 °C, the EAB of the FeCoNiCuC0.37 is further increased to 7.99 GHz at 1.95 mm, which is better than that of most HEA‐based EMA absorbers reported so far. Moreover, it demonstrates excellent corrosion resistance owing to the more tortuous diffusion path of corrosive medium origin from lattice distortion. Thus, the study provides a new insight into designing high performance HEA‐based EMA materials with superior anti‐corrosion property by lattice distortion engineering. [ABSTRACT FROM AUTHOR]

Copyright of Atomic Energy Science & Technology is the property of Editorial Board of Atomic Energy Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BaTiO3, as a perovskite type material with excellent chemical stability and suitable conduction, has been widely studied in the field of photocatalysis. However, it can only absorb ultraviolet light because of its wide band gap. Herein, the lifetime of photogenerated electrons of BaTiO3 doped with Ta5+ can be enhanced. To study the band structure and photocatalytic performance of Ta‐doped BaTiO3, sol‐gel assisted solid‐phase method was employed to prepare BaTiO3 doped with varying Ta5+ doping amounts, and the structure characteristic and formation mechanism of the Ta‐doped BaTiO3 were analyzed. The results showed that the heat treatment temperature reached 1052.7 °C, sufficient thermodynamic conditions were obtained for Ta5+ to dope into the BaTiO3 lattice, and lattice distortion occurred in BaTiO3. Meanwhile, the particle size after doping decreased with the increase of Ta5+ doping amount. The 1.25 mol %Ta5+‐doped BaTiO3 had the lowest band gap (3.077 eV), and the photocatalytic water splitting had the best hydrogen evolution activity, which was 2.4 times that of BaTiO3. Furthermore, the conductance potential of 1.25 mol %Ta5+‐doped BaTiO3 was more negative than that of BaTiO3, which improved the thermodynamic advantage of the photocatalytic water splitting, and it had higher and more stable photoresponse and photogenerated carrier migration rate. [ABSTRACT FROM AUTHOR]

The bulk Na5Lu9F32 single crystals with high quality serial Eu3+/Gd3+ co‐doped were grown by an ameliorative Bridgman technique. The measurement of X‐ray diffraction (XRD) and analysis of Rietveld refinement were implemented to validate the crystal phase. The Eu3+ doped Na5Lu9F32 single crystal emits intense red emission at 611 nm excited by 394 nm light. The intensity of 1.8 mol % Gd3+ doped sample is boosted by 3.56 times compared with the un‐doped one. The doping of Gd3+ ions replace competitively Lu3+ lattice sites with Eu3+ ions. Thus, they cause the lattice distortion and reduction of symmetry, enabling Eu3+ ions to overcome their 4f forbidden transitions. The change of Eu3+ ion local environment induced by Gd3+ ion doping was explored by the Eu3+ emission spectra and the variations of ratios between red and orange emission intensities (R/O). The fluorescence lifetime indicates that the introduction of GdF3 decreases the probability of non‐radiative transitions and increases the fluorescence lifetime. These results demonstrated that the Na5Lu9F32: Eu3+ single crystal doped with an appropriate concentration of GdF3 is a type of promising red emission single crystal for related optical devices of detector and laser due to its strong red emission, high transparency and high physico‐chemical stability. [ABSTRACT FROM AUTHOR]

Bismuth titanate (BIT) is widely known as one of the most prospective lead‐free ferroelectric and piezoelectric materials in advanced high‐temperature sensing applications. Despite significant advances in developing BIT ferroelectrics, it still faces major scientific and engineering challenges in realizing super‐high performance to meet next‐generation high‐sensitivity and light‐weight applications. Here, a novel ferroelectric domain‐engineered BIT ceramic system is conceived that exhibits super‐high piezoelectric coefficient (d33 = 38.5 pC N−1) and inverse piezoelectric coefficient (d33* = 46.7 pm V−1) at low electric field as well as excellent fatigue resistance (stable up to 107 cycles). The results reveal that the introduction of high‐density layered (001)‐type 180° domain walls with flexible polarization rotation features and the formation of small‐size multi‐domain states with low energy barriers are mainly responsible for the excellent electrical performance. To the best of knowledge, it is the first time to reveal such intriguing domain structures in BIT ceramics in detail, especially from the atomic‐scale perspective by using atomic number (Z)‐contrast imaging in combination with atomic‐resolution polarization mapping. It is believed that this breakthrough conduces to comprehensively understand structural features of ferroelectric domains in BIT ceramics, and also opens a window for future developments of super‐high performance in bismuth layer‐structured ferroelectrics via domain engineering. [ABSTRACT FROM AUTHOR]

CrAlN and CrAlBN coatings were prepared on the surface of high-speed steel and shaper cutter by physical vapor deposition (PVD) technique using arc ion source. In the process of coating preparation, the adhesive layers were deposited by low bias voltage (−40 V) and the working layers are deposited by high bias voltage (−130 V). The effects of the addition of B element on the microstructure, hardness, elastic modulus and wear resistance of CrAlBN coating were studied. The results show that B element and its compounds exist in amorphous form in the coating, resulting in lattice distortion of the coating, increase of coating hardness to 37.1 GPa, and decrease of elastic modulus to 406.2 GPa. The addition of B element increases the uniformity of the columnar structure distribution and decreases the width of the columnar structure and grain size. The resistance to elastic deformation and plastic deformation of CrAlBN coating is improved, the wear resistance is improved. The performance of CrAlN and CrAlBN coatings on shaper cutter was studied. It was found that the main failure mode of shaper cutters is boundary wear and the wear mechanism of coatings had changed obviously. CrAlBN coating is mainly due to fatigue induced failure, accompanied by some diffusion wear. The addition of B element makes the CrAlBN coating have excellent resistance to oxidative wear, abrasive wear and diffusion wear during cutting. The results show that the addition of B element can improve the microstructure and mechanical properties of CrAlN coating, and the preparation of CrAlBN coating on the surface of the shaper cutter can significantly improve the service life of the coated shaper cutter, which has significance for the development of the shaper cutter industry. [ABSTRACT FROM AUTHOR]

Here, a novel aluminum-gallium-phosphate (GAHPO) metal-inorganic framework structure was prepared by hydrothermal method, and it was fully characterized by single crystal X-ray diffraction, powder X-ray diffraction, IR spectroscopy, and gravimetric analysis-differential scanning calorimeter (TG-DSC). Single crystal X-ray diffraction results show that GAHPO is attributed to the trigonal system and Rc3 space group. Al(Ga) O6 octahedra and PO4 tetrahedral structures is distorted to form one-dimensional chains, and then is stacked into three-dimensional metal-inorganic frameworks through hydrogen bonding. TG-DSC shows that GAHPO is of high thermal stability, with the initial decomposition temperature of 240 ²C. Compared with aluminum phosphate, the introduction of Ga3+ distorted the AlPO4 lattice, thus weakening and elongating the Al--O bond, which makes more acid catalytic sites exposed and enhanced the catalytic activity. The experiment shows that when the reaction temperature is 60 ²C, and the catalyst dosage is 10% of acetaldehyde, GAHPO could catalyze the condensation of acetaldehyde to produce butanolal with good conversion rate (47%) and excellent selectivity ( >99%). The reaction mechanism of acetaldehyde condensation catalyzed by GAHPO was investigated using scavengers, NH3-TPD and specially designed derivatives to confirm the reactive sites of the catalyst and the substrate. This work provides a feasible way for novel aluminum inorganic framework structures and the catalytic applications. [ABSTRACT FROM AUTHOR]

Electric field (E) control of magnetism is a persistent challenge in low-power consumption spintronic devices. A promising way to realize this control is to use the conversemagnetoelectric (ME) effect in insulating multiferroics.Here,we report considerable and repeatable E-modulated magnetization (M) at room temperature and even at 350 K via the significantly enhanced converseME effect near the morphotropic phase boundary (MPB) of the Cr-Mn co-doped (1-y)BiFe1-xCrxO3- yBaTi1-xMnxO3 (0.15 ≤ y ≤ 0.33, 0 ≤ x ≤ 0.03) solid solutions. In situ X-ray diffraction and Raman scattering experiments at different applied E for the sample near the MPB (i.e., y = 0.27, x = 0.03) show E-induced shift, broadening, and splitting in the {002}PC reflection, as well as a nearly monotonous variation in intensity of several phonon modes with E, reminiscent of the E-dependent M behavior. These results indicate that both E-induced lattice distortion and phase transformation dominate the converseME effects in these samples. Our demonstration of the E-regulation of magnetism via the E-sensitive crystal structures in designed insulating multiferroics near MPB may suggest a potential route to obtain efficient low-power spintronic devices. [ABSTRACT FROM AUTHOR]

High-performance lead-free piezoelectric thin films are urgently required for microelectromechanical systems. In this study, thin films based on the 0.8Bi0.5Na0.5TiO3-0.2(Sr0.7Bi0.20.1)TiO3 system were prepared on Pt(111)/TiOx/SiO2/Si substrates by a sol--gel method. The large lattice distortions were induced by introducing five rare-earth ions with different ionic radii (Er/Pr/Sm/Nd/La) to achieve the purpose of regulating the piezoelectric response of the thin films with the maximum inverse piezoelectric coefficient up to 425.9 pm/V. X-ray diffraction, Raman spectroscopy, Piezoresponse force microscope, and additional testing methods were used to observe the phase composition and microstructure of the thin films to investigate the effect of doping rare-earth elements with different ionic radii at the A-site on lattice distortion, and to summarize the transformation law. This study is significant for improving the piezoelectric properties of thin films and has crucial applications in microelectronic sensing. [ABSTRACT FROM AUTHOR]

The production of formic acid via electrochemical CO2 reduction may serve as a key link for the carbon cycle in the formic acid economy, yet its practical feasibility is largely limited by the quantity and concentration of the product. Here we demonstrate continuous electrochemical CO2 reduction for formic acid production at 2 M at an industrial‐level current densities (i.e., 200 mA cm−2) for 300 h on membrane electrode assembly using scalable lattice‐distorted bismuth catalysts. The optimized catalysts also enable a Faradaic efficiency for formate of 94.2 % and a highest partial formate current density of 1.16 A cm−2, reaching a production rate of 21.7 mmol cm−2 h−1. To assess the practicality of this system, we perform a comprehensive techno‐economic analysis and life cycle assessment, showing that our approach can potentially substitute conventional methyl formate hydrolysis for industrial formic acid production. Furthermore, the resultant formic acid serves as direct fuel for air‐breathing formic acid fuel cells, boasting a power density of 55 mW cm−2 and an exceptional thermal efficiency of 20.1 %. [ABSTRACT FROM AUTHOR]

The production of formic acid via electrochemical CO2 reduction may serve as a key link for the carbon cycle in the formic acid economy, yet its practical feasibility is largely limited by the quantity and concentration of the product. Here we demonstrate continuous electrochemical CO2 reduction for formic acid production at 2 M at an industrial‐level current densities (i.e., 200 mA cm−2) for 300 h on membrane electrode assembly using scalable lattice‐distorted bismuth catalysts. The optimized catalysts also enable a Faradaic efficiency for formate of 94.2 % and a highest partial formate current density of 1.16 A cm−2, reaching a production rate of 21.7 mmol cm−2 h−1. To assess the practicality of this system, we perform a comprehensive techno‐economic analysis and life cycle assessment, showing that our approach can potentially substitute conventional methyl formate hydrolysis for industrial formic acid production. Furthermore, the resultant formic acid serves as direct fuel for air‐breathing formic acid fuel cells, boasting a power density of 55 mW cm−2 and an exceptional thermal efficiency of 20.1 %. [ABSTRACT FROM AUTHOR]

The commercialization of high‐performance nickel‐rich cathodes always awaits a cost‐effective, environmentally friendly, and large‐scale preparation method. Despite a grinding process normally adopted in the synthesis of the nickel‐rich cathodes, lattice distortion, rough surface, and sharp edge transformation inevitably occurr in the resultant samples. In this work, an additional annealing process is proposed that aims at regulating lattice distortion as well as achieving round and smoother morphologies without any structural or elemental modifications. Such a structural enhancement is favored for improved lithium diffusion and electrochemical stability during cycling. Consequently, the annealed cathodes demonstrate a considerable enhancement in capacity retention, escalating from 68.7% to 91.9% after 100 cycles at 1 C. Additionally, the specific capacity is significantly increased from 64 to 142 mAh g−1 at 5 C when compared to the unannealed cathodes. This work offers a straightforward and effective approach for reinforcing the electrochemical properties of nickel‐rich cathodes. [ABSTRACT FROM AUTHOR]

Charge density wave (CDW) is a phenomenon that occurs in materials, accompanied by changes in their intrinsic electronic properties. The study of CDW and its modulation in materials holds tremendous significance in materials research, as it provides a unique approach to controlling the electronic properties of materials. TiSe2 is a typical layered material with a CDW phase at low temperatures. Through V substitution for Ti in TiSe2, we tuned the carrier concentration in VxTi1−xSe2 to study how its electronic structures evolve. Angle-resolved photoemission spectroscopy (ARPES) shows that the band-folding effect is sustained with the doping level up to 10%, indicating the persistence of the CDW phase, even though the band structure is strikingly different from that of the parent compound TiSe2. Though CDW can induce the band fold effect with a driving force from the perspective of electronic systems, our studies suggest that this behavior could be maintained by lattice distortion of the CDW phase, even if band structures deviate from the electron-driven CDW scenario. Our work provides a constraint for understanding the CDW mechanism in TiSe2, and highlights the role of lattice distortion in the band-folding effect. [ABSTRACT FROM AUTHOR]

Highlights: A percolating network of distorted 2D Pt nanomembranes was synthesized by polymer surface buckling-enabled exfoliation for hydrogen evolution reaction. The 2D Pt nanomembrane enabled important technological applications for its high efficiency, low costs, and good stability, making it potential alternative to commercial Pt/C. Our 2D Pt nanomembranes offer insights into a new mechanism for efficient catalyst design strategy: lattice distortion-induced heterogeneous strain. Hydrogen production through hydrogen evolution reaction (HER) offers a promising solution to combat climate change by replacing fossil fuels with clean energy sources. However, the widespread adoption of efficient electrocatalysts, such as platinum (Pt), has been hindered by their high cost. In this study, we developed an easy-to-implement method to create ultrathin Pt nanomembranes, which catalyze HER at a cost significantly lower than commercial Pt/C and comparable to non-noble metal electrocatalysts. These Pt nanomembranes consist of highly distorted Pt nanocrystals and exhibit a heterogeneous elastic strain field, a characteristic rarely seen in conventional crystals. This unique feature results in significantly higher electrocatalytic efficiency than various forms of Pt electrocatalysts, including Pt/C, Pt foils, and numerous Pt single-atom or single-cluster catalysts. Our research offers a promising approach to develop highly efficient and cost-effective low-dimensional electrocatalysts for sustainable hydrogen production, potentially addressing the challenges posed by the climate crisis. [ABSTRACT FROM AUTHOR]

It is well demonstrated that the complex chemical fluctuations on high/medium-entropy alloys (H/MEAs) play critical roles in their deformation process, but there are few reports related to the effect of such complex chemical fluctuations on the crack behavior. In this paper, the effects of chemical short-range order (CSRO) and lattice distortion (LD) on the crack-tip behavior of CrCoNi MEAs under mode I loading at room temperature are investigated by carrying out molecular dynamics (MD) simulation, hybrid MD/Monte-Carlo (MC) simulation and the J-integral method. The results reveal that CSRO can improve the J-integral value without significant changes in the localized deformation zone size. On the contrary, LD can lower the J-integral value with an increase in the localized deformation zone size. The energetic analysis shows that CSRO improves the activation energy barrier of Shockley partial dislocation from the crack-tip while LD reduces the activation energy barrier. Our work is a step forward in understanding the effects of CSRO and LD on the crack-tip behavior and deformation mechanisms of CrCoNi MEAs. [ABSTRACT FROM AUTHOR]

Owing to their adaptable topologies and simplicity of functionalization, metal–organic frameworks (MOFs) are highly sought-after materials for battery-type electrodes. To improve the MOFs' overall conductivity and instability, a Ni/Co-MOF nanostructure grows in situ on nickel foam (NF) with the controlled introduction of structural defects using a one-step solvothermal method. Benzoic acid (BA) is selected as the cost-effective regulator and ligand to compete with the original ligand terephthalic acid (TPA), for inducing lattice distortion. The incorporation of BA results in increased micropore volume and surface area. These characteristics improve the contact between the electrode and electrolyte, leading to a rapid redox reaction. Thus, the defective sample Ni/Co-MOF/NF with 10% BA exhibits an ultrahigh capacity of 352.3 mAh g–1 at a current density of 1 A g–1. Moreover, the assembled hybrid supercapacitor device (10% Ni/Co-MOF/NF//AC) demonstrates a suitable energy density of 33.5 Wh kg–1 at a power density of 404.6 W kg–1 and 90.3% capacitance retention after 8000 cycles. These findings provide valuable insights for developing ultrahigh-performance MOF nanostructures that can be directly used as supercapacitor electrodes. [ABSTRACT FROM AUTHOR]

The microstructure of nanostructured bainite formed by austempering in high-carbon silicon steel is characterized by high resolution electron microscopy. The results show that the bainitic sheaves consist of nanoscale subunits. The found kinds of crystal lattice distortions of each subunit in one bainite lath show clear difference. The latest generated subunit has most distortions. As the subunit grows up, the lattice distortion gradually gets relaxed. This indicates that the subunits form with high phase transformation strain energy, which causes severe lattice distortion. The results provide new experimental evidence on subjects relevant to the understanding of the mechanism of formation of bainitic ferrite. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The new (0.96‐x)(K0.48Na0.52Nb0.96Sb0.04)O3‐0.04(Bi0.5Ag0.5)ZrO3‐x(Fe2O3‐In2O3) ceramics with high dielectric, and electromechanical coupling properties were designed. In this work, the effect of KNN‐based ceramics lattice distortion (c/a) and microstructure on the electrical properties was explored by varying the doping amount of Fe3+ and In3+. The problem of a large number of oxygen vacancies generated by the volatilization of K and Na can be well solved by introducing Fe3+ and In3+. The bulk density increases significantly and the maximum value is about 4.52 g/cm3.The sample with x = 0.003 has the smallest c/a, and exhibits the best piezoelectric and dielectric properties (d33 = 536 pC/N, εr = 3432 and kp = 55.8 %). Low doping concentration of Fe2O3 is considered a "soft" addition for KNN‐based piezoelectric ceramics. The study of this mechanism provides a new idea to regulate the electrical performance of KNN‐based ceramics. [ABSTRACT FROM AUTHOR]

The exploration of inexpensive and efficient catalysts for oxygen reduction reaction (ORR) is crucial for chemical and energy industries. Carbon materials have been proved promising with different catalysts enabling 2 and 4e− ORR. Nevertheless, their ORR activity and selectivity is still complex and under debate in many cases. Many structures of these active carbon materials are also chemically unstable for practical implementations. Unlike the well‐discussed structures, this work presents a strategy to promote efficient and stable 2e− ORR of carbon materials through the synergistic effect of lattice distortion and H‐passivation (on the distorted structure). We show how these structures can be formed on carbon cloth, and how the reproducible chemical adsorption can be realized on these structures for efficient and stable H2O2 production. The work here gives not only new understandings on the 2e− ORR catalysis, but also the robust catalyst which can be directly used in industry. [ABSTRACT FROM AUTHOR]

The exploration of inexpensive and efficient catalysts for oxygen reduction reaction (ORR) is crucial for chemical and energy industries. Carbon materials have been proved promising with different catalysts enabling 2 and 4e− ORR. Nevertheless, their ORR activity and selectivity is still complex and under debate in many cases. Many structures of these active carbon materials are also chemically unstable for practical implementations. Unlike the well‐discussed structures, this work presents a strategy to promote efficient and stable 2e− ORR of carbon materials through the synergistic effect of lattice distortion and H‐passivation (on the distorted structure). We show how these structures can be formed on carbon cloth, and how the reproducible chemical adsorption can be realized on these structures for efficient and stable H2O2 production. The work here gives not only new understandings on the 2e− ORR catalysis, but also the robust catalyst which can be directly used in industry. [ABSTRACT FROM AUTHOR]

The lattice of wurtzite nitrides such as gallium nitride (GaN) and aluminum nitride (AlN) is distorted by alloying with scandium (Sc). This lattice distortion, which entails a decrease in the lattice constant ratio c/a, leads to a significant improvement in piezoelectricity and the appearance of ferroelectricity, which are attractive properties for material applications. However, systematic studies on the effect of different alloying elements on the lattice distortion of wurtzite nitrides are scarce and restricted to theoretical investigations. Herein, the experimental investigation of the lattice distortion and its influence on the piezoelectricity of cosputtering‐prepared thin films of GaN alloyed with group III and rare‐earth elements other than Sc, that is, yttrium, dysprosium, and ytterbium is described. All the investigated elements greatly reduce the lattice constant ratio of GaN from 1.63 to 1.61 and cause a twofold increase in the piezoelectric charge coefficient. Therefore, it is indicated in the experimental results that alloying with elements other than Sc also results in the distortion of the crystal lattice and the enhancement of the piezoelectric properties of GaN. Furthermore, regardless of the particular alloying element used, a correlation between lattice distortion and piezoelectricity is experimentally demonstrated. [ABSTRACT FROM AUTHOR]

The rapid evolution in materials science has resulted in a significant interest in high-entropy alloys (HEAs) for their unique properties. This study focuses on understanding both quaternary and quinary body-centered cubic (BCC) of 12 refractory-based HEAs, and on analysis of their electronic structures, lattice distortions, mechanical, and thermal properties. A comprehensive assessment is undertaken by means of density functional theory (DFT)-based first principles calculations. It is well known that multiple constituents lead to notable lattice distortions, especially in quinary HEAs. This distortion, in turn, has significant implications on the electronic structure that ultimately affect mechanical and thermal behaviors of these alloys such as ductility, lattice thermal conductivity, and toughness. Our in-depth analysis of their electronic structures revealed the role of valence electron concentration and its correlation with bond order and mechanical properties. Local lattice distortion (LD) was investigated for these 12 HEA models. M1 (WTiVZrHf), M7 (TiZrHfW), and M12 (TiZrHfVNb) have the highest LD whereas the models M3 (MoTaTiV), M5 (WTaCrV), M6 (MoNbTaW), and M9 (NbTaTiV) have the less LD. Furthermore, we investigated the thermal properties focusing on Debye temperature (ΘD), thermal conductivity (κ), Grüneisen parameter (γα), and dominant phonon wavelength (λdom). The NbTaTiV(M9) and TiVNbHf(M10) models have significantly reduced lattice thermal conductivities (κL). This reduction is due to the mass increase and strain fluctuations, which in turn signify lattice distortion. The findings not only provide an understanding of these promising materials but also offer guidance for the design of next-generation HEAs with properties tailored for potential specific applications. [ABSTRACT FROM AUTHOR]

The cohesive performance and durability of the bonding layer with semiconductor substrates are of paramount importance for realizing the high thermal conductivity capabilities of diamond. Utilizing electron beam evaporation and the room-temperature, low-pressure bonding process, robust adhesion between diamonds and silicon substrates has been achieved through the application of the metal modification layer comprised of Ti/Cu/Ti/Au (5/300/5/50 nm). Characterization with optical microscopy and atomic force microscopy reveals the uniformity and absence of defects on the surface of the deposited layer. Observations through X-ray and scanning acoustic microscopy indicate no discernible bonding defects. Scanning electron microscopy observation and energy-dispersive spectroscopy analysis of the fracture surface show distinct fracture features on the silicon substrate surface, indicating that the bonding strength of the Ti/Cu/Ti/Au metallization layer surpasses that of the base material. Furthermore, the fracture surface exhibits the presence of Cu and trace amounts of Ti, suggesting that the fracture also occurs at the interface between Ti and Cu. Characterization of the metal modification layer using X-ray diffraction reveals significant lattice distortion in the Ti layer, leading to noticeable stress accumulation within the crystalline structure. Thermal–mechanical fatigue simulations of the Ti/Cu/Ti/Au metal modification layer indicate that, owing to the difference in the coefficient of thermal expansion, the stress exerted by the Cu layer on the Ti layer results in the accumulation of fatigue damage within the Ti layer, ultimately leading to a reduction in its strength and eventual failure. [ABSTRACT FROM AUTHOR]

The family of two-dimensional (2D) layered materials with strong excitonic effect offers fascinating opportunities for studying excited state exciton behavior at 2D limit. While exciton dynamics in conventional 2D semiconductors (e.g. transition metal dichalcogenides) has been extensively studied, little is known about exciton properties and dynamics in 2D layered semiconductors with strong electron/exciton-phonon coupling. Here, by combining experimental and theoretical approaches, we reveal the intrinsic highly localized exciton (i.e. self-trapped exciton) in 2D layered As2S3, driven by strong exciton-phonon interaction. It is shown that photoexcited electron/hole charges in As2S3 localize spontaneously in ~110 fs, giving rise to large stokes-shifted and broad photoluminescence. An interlayer partial bond is formed between chalcogen atoms, triggering lattice distortion and carrier localization. Together with Urbach-Martienssen analysis, this study provides a comprehensive physical picture to understand the complex interplay between exciton and lattice dynamics in 2D semiconductors, which has strong implications to their optoelectronic properties and applications. [ABSTRACT FROM AUTHOR]

Although severe lattice distortion is one of the core effects of multicomponent materials, accurate quantitative description is still an open issue. In this paper, density functional theory (DFT) calculations based on special quasi-random structure (SQS) are used to investigate the lattice distortion of multicomponent (TiZrHf)C and (TiZrHf)N ceramics, and the influences on structural, mechanical, electronic and thermodynamic properties. The distortion in (TiZrHf)C and (TiZrHf)N is quantified by the average atomic displacement and the bond length distribution. Our results show that the distortion in (TiZrHf)N is greater than in (TiZrHf)C. Lattice distortion can improve thermodynamic stability while enhancing ductility at the expense of strength and hardness. Moreover, the influence of lattice distortion on thermal properties is further studied, suggesting that the distortion increases the vibrational entropy due to the high-temperature softening of the lattice, thereby increasing the total entropy and thermodynamic stability of ceramics. After distortion, the thermal expansion coefficient is obviously larger and the heat capacity CV and CP also increase, especially at low temperatures. Therefore, the present study is valuable for understanding and optimization of the comprehensive properties of multicomponent ceramics by tuning the lattice distortion effect. [ABSTRACT FROM AUTHOR]

High‐entropy single‐phase rare earth titanates (RE0.2Gd0.2Ho0.2Er0.2Yb0.2)2Ti2O7 (RE = Sm, Y, Lu) were designed and synthesized successfully, in which their lattice distortion was quantitatively described by mass disorder and size disorder. It is worth mentioning that (Y0.2Gd0.2Ho0.2Er0.2Yb0.2)2Ti2O7 could obtain the low thermal conductivity (1.51 W·m−1·K−1, 1500°C), high thermal expansion coefficient (average, 11.69×10−6 K−1, RT ∼1500°C) and excellent high‐temperature stability. In addition, the relationship between the microstructure and thermal transport behaviors has been studied at the atomic scale. Due to the disorder of A‐site ions, severe lattice distortion occurred in specific crystal planes, and the large mass difference between Y3+ and other RE3+ further causes mass fluctuation and results in lower thermal conductivity. Compared with YSZ, the high‐entropy rare earth titanate (Y0.2Gd0.2Ho0.2Er0.2Yb0.2)2Ti2O7 has lower thermal conductivity, higher thermal expansion coefficient, and excellent high‐temperature stability, which has great potential for application in the thermal protection field. [ABSTRACT FROM AUTHOR]

As a new type of high‐entropy material, most of the current work has focused on the synthesis and characterization of mechanical properties of high‐entropy diboride ceramics (HEBs). In this work, single‐phase HEBs with 5–9 cations were prepared by spark plasma sintering with self‐synthesized HEB powders through the boro/carbothermal reduction method. The distribution of the metal elements in the obtained HEBs was homogeneous. Due to the phonon scattering caused by the inherent lattice distortion in the HEBs, the thermal conductivity of the ceramics decreased with the increased configurational entropy or the number of cation kinds. However, this study reveals that the degree of reduction in thermal conductivity for the HEBs demonstrate a weakened tendency with cation kinds of more than 6. [ABSTRACT FROM AUTHOR]

The rapid advancement of big data, artificial intelligence, and cloud computing technologies has led to a significant increase in demand for high-density magnetic storage. High-entropy alloys offer better control over the properties of magnetic storage materials, allowing for a wider range of magnetic configurations. In this study, a five-membered magnetic alloy was created using powder metallurgy. It was revealed that both FeCrCoSiGe and FeMnCoSiGe alloys are dual-phase high-entropy alloys consisting of B20 CoGe- and FeSi-based phases. The study also demonstrated an interesting "kink" feature observed in the temperature-dependent magnetization of FeCrMnSiGe that suggests a potential association with helimagnetism. The helimagnetism is from the intrinsic helical ferromagnetism in the CoGe matrix phase and varies with the magnetic interactions due to the doped atoms. Furthermore, the temperature-dependent magnetization showed that replacing chromium (Cr) with cobalt (Co) could potentially reduce the magnetization transition to approximately 60 K. A complete substitution of chromium with manganese (Mn) could also alter the magnetic transition behavior. FeCrMnSiGe, FeCrCoSiGe, and FeMnCoSiGe were identified as soft magnets based on their field-dependent magnetization. The magnetic properties could be adjusted by modifying the composition and lattice distortion of the alloy. This study has the potential to aid in the development of a new material system with an adjustable chiral magnetic structure for spintronic memory devices. [ABSTRACT FROM AUTHOR]

Face-centered cubic (f.c.c.) high entropy alloys (HEAs) are attracting more and more attention owing to their excellent strength and ductility synergy, irradiation resistance, etc. However, the yield strength of f.c.c. HEAs is generally low, significantly limiting their practical applications. Recently, the alloying of W has been evidenced to be able to remarkably improve the mechanical properties of f.c.c. HEAs and is becoming a hot topic in the community of HEAs. To date, when W is introduced, multiple strengthening mechanisms, including solid-solution strengthening, precipitation strengthening (μ phase, σ phase, and b.c.c. phase), and grain-refinement strengthening, have been discovered to be activated or enhanced. Apart from mechanical properties, the addition of W improves corrosion resistance as W helps to form a dense WO3 film on the alloy surface. Until now, despite the extensive studies in the literature, there is no available review paper focusing on the W doping of the f.c.c. HEAs. In that context, the effects of W doping on f.c.c. HEAs were reviewed in this work from three aspects, i.e., microstructure, mechanical property, and corrosion resistance. We expect this work can advance the application of the W alloying strategy in the f.c.c. HEAs. [ABSTRACT FROM AUTHOR]

The interplanar spacings and unit cell parameters of CIβ crystallites are not constant but vary within a limited range of values. Such structural changes are caused by the distortion of the crystal lattice. It was shown that the paracrystalline fraction of crystallites introduces the main contribution to the distortion of the crystalline lattice. The decrease in the content of this fraction led to the reduction in distortion parameters, interplanar spacings, and the volume of the crystalline unit cell. As a result, the undistorted crystalline unit cell of CIβ macrocrystals can be proposed with the following parameters: ao= 0.772 nm, bo= 0.815 nm, co=1.040 nm, γo =96.5o. In addition, the specific volume and specific gravity of such macrocrystals, Vc,o = 0.604 cm³/g and Gc,o = 1.655 g/cm³ were calculated. It was also found that by knowing the content of the paracrystalline fraction in the CIβ crystallites, one can predict several important properties of cellulose. [ABSTRACT FROM AUTHOR]

Glycerol oxidation reaction (GOR) coupled with hydrogen generation simultaneously is a promising strategy for developing sustainable energy conversion technologies, but the complexity of glycerol oxidation products and the high coupling hydrogen evolution potential limit its wide application. In this paper, a self-supported high-entropy selenide electrode can be fabricated via a simple hydrothermal process. Then, the prepared electrode as an advanced catalyst displays optimal catalytic activity (1.20 V at 10 mA·cm−2) and high selectivity for the formation of formate in GOR. The results show that the lattice distortion effect of high entropy materials composed of multiple elements is mainly responsible for the greatly improved catalytic activity and selectivity for GOR. Moreover, an advanced alkali-acid hybrid electrolytic cell was assembled that enables efficient energy-saving hydrogen generation and GOR simultaneously. Herein, the electrolyzer requires only 0.5 V applied voltage to reach 10 mA·cm−2 for hydrogen generation and maintains long-term operation stability. [ABSTRACT FROM AUTHOR]

In this paper, with the synergistic effect of C, Co and O elements, and with a one-dimensional carbon nanotube (CNT) as the structure guide agent, a two-dimensional Co3O4 nano-sheet with high catalytic activity was prepared, and its catalytic activity was further improved by adding a manganese element. By controlling the annealing time, a two-dimensional Co3O4-based nano-sheet with a regular arrangement of atoms on the surface was gradually formed during the oxidation process of CNT. Then, the lattice distortion of Co3O4 was caused by doping manganese. The interaction between Mn and Co promotes the cycle capacity of Mn/Co redox pair and the generation of reactive oxygen species, which is conducive to an improvement in catalytic activity. Finally, under different catalytic conditions, the 2D Co3O4-based catalysts all showed stable catalytic performances, among which methane flow rate had a great influence. When the airspeed was controlled within the range of 42,000 mL·g−1·h−1, the methane conversion rate could still reach 90% (450 °C). [ABSTRACT FROM AUTHOR]

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Copyright of Journal of Synthetic Crystals is the property of Journal of Synthetic Crystals Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effects of carbon distribution on the microstructure and thermal conductivity of ductile iron were investigated in the present study. The microstructure of as-cast and quenched ductile iron were characterized by OM and SEM. Results showed that the microstructure of as-cast ductile iron was composed of spheroidal graphite, ferrite with the volume of 80%, and a small amount of pearlite, and quenched ductile iron was composed of spheroidal graphite, coarse/fine acicular martensite (αM phase) and high-carbon retained austenite (γ phase). The volume fraction of retained austensite and its carbon content for direct quenched ductile iron and tepmered ductile iron were quantitatively analysed by XRD. Results revealed that carbon atoms diffused from αM phase to γ phase during tempering at low temperatures, which resulted in carbon content in retained γ phase increasing from 1.2 wt% for the direct quenched sample to about 1.9 wt% for the tempered samples. Consequently, the lattice distortion was significantly reduced and gave rise to an increase of thermal conductivity for ductile iron. [ABSTRACT FROM AUTHOR]

Ruddlesden–Popper perovskites (RPPs) feature enhanced stability compared to their bulk counterparts and attract attention for potential applications in light‐emitting diodes (LEDs). However, to date, blue‐emitting RPPs rely on halide compositional tuning, resulting in spectral shifts due to halide segregation under photo‐/electrical‐excitation. Here, efficient blue‐emitting materials with single‐halide RPPs using organic spacer engineering are reported. Experimental and computational results show that the (110)‐oriented thin films exhibit larger bandgap and enhanced stability regardless of the choice of spacers, relative to the (100)‐oriented RPPs. The correlation between the lattice structures and optoelectronic properties reveals that this new class of RPPs exhibits sky‐blue emission at 483 nm with a quantum efficiency of ≈62%. Spearman correlation between the steric size of the spacers and the bandgap is estimated to be 92%, showing that the steric effect is crucial influencers. The protocol and strategy established in this study can be exploited to develop blue perovskite LEDs. [ABSTRACT FROM AUTHOR]

A pseudosymmetric description of the crystal lattice derived from a single wide‐angle Kikuchi pattern can have several causes. The small size (<15%) of the sector covered by an electron backscatter diffraction pattern, the limited precision of the projection centre position and the Kikuchi band definition are crucial. Inherent pseudosymmetries of the crystal lattice and/or structure also pose a challenge in the analysis of Kikuchi patterns. To eliminate experimental errors as much as possible, simulated Kikuchi patterns of 350 phases have been analysed using the software CALM [Nolze et al. (2021). J. Appl. Cryst.54, 1012–1022] in order to estimate the frequency of and reasons for pseudosymmetric crystal lattice descriptions. Misinterpretations occur in particular when the atomic scattering factors of non‐equivalent positions are too similar and reciprocal‐lattice points are systematically missing. As an example, a pseudosymmetry prediction depending on the elements involved is discussed for binary AB compounds with B1 and B2 structure types. However, since this is impossible for more complicated phases, this approach cannot be directly applied to compounds of arbitrary composition and structure. [ABSTRACT FROM AUTHOR]

Ni‐rich layered oxides are one of the most attractive cathode materials in high‐energy‐density lithium‐ion batteries, their degradation mechanisms are still not completely elucidated. Herein, we report a strong dependence of degradation pathways on the long‐range cationic disordering of Co‐free Ni‐rich Li1−m(Ni0.94Al0.06)1+mO2 (NA). Interestingly, a disordered layered phase with lattice mismatch can be easily formed in the near‐surface region of NA particles with very low cation disorder (NA‐LCD, m≤0.06) over electrochemical cycling, while the layered structure is basically maintained in the core of particles forming a "core–shell" structure. Such surface reconstruction triggers a rapid capacity decay during the first 100 cycles between 2.7 and 4.3 V at 1 C or 3 C. On the contrary, the local lattice distortions are gradually accumulated throughout the whole NA particles with higher degrees of cation disorder (NA‐HCD, 0.06≤m≤0.15) that lead to a slow capacity decay upon cycling. [ABSTRACT FROM AUTHOR]

Ni‐rich layered oxides are one of the most attractive cathode materials in high‐energy‐density lithium‐ion batteries, their degradation mechanisms are still not completely elucidated. Herein, we report a strong dependence of degradation pathways on the long‐range cationic disordering of Co‐free Ni‐rich Li1−m(Ni0.94Al0.06)1+mO2 (NA). Interestingly, a disordered layered phase with lattice mismatch can be easily formed in the near‐surface region of NA particles with very low cation disorder (NA‐LCD, m≤0.06) over electrochemical cycling, while the layered structure is basically maintained in the core of particles forming a "core–shell" structure. Such surface reconstruction triggers a rapid capacity decay during the first 100 cycles between 2.7 and 4.3 V at 1 C or 3 C. On the contrary, the local lattice distortions are gradually accumulated throughout the whole NA particles with higher degrees of cation disorder (NA‐HCD, 0.06≤m≤0.15) that lead to a slow capacity decay upon cycling. [ABSTRACT FROM AUTHOR]

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The development of industry has triggered an increasingly severe demand for new functional materials. In recent years, researches on high‐entropy oxides (HEOs) are more comprehensive and in‐depth, and their fascinating properties are gradually known to the public. The unique elemental synergistic effect and lattice distortion endow the high‐entropy family with various untapped potential, and wide application fields and outstanding performance of HEOs make them candidates for future materials. In this review, the concept, structure, and synthesis of HEOs are firstly highlighted. Secondly, a variety of excellent properties and applications in the fields of mechanics, electrics, thermotics, optics and magnetics are summarized. This work provides a comprehensive overview about HEOs, facilitating the development of modern functionalities of the high‐entropy family. [ABSTRACT FROM AUTHOR]

Materials with magnetic phase transitions have attracted considerable attention in magnetic storage, magnetic drive, magnetic sensor, and solid-state refrigeration applications owing to the correlated changes in their physical properties. To explore the magnetic transitions in materials with a B20 structure with potential for spintronic applications, ternary semiconductors FeSi1−xGex (x = 0.1, 0.25, 0.5, 0.75, and 0.9) were prepared. The results confirmed that the FeSi1−xGex ternary material system contains a Si-rich phase with a crystal structure matching B20 FeSi, a Ge-rich phase with a crystal structure matching B20 FeGe, and FeGe2 with a tetragonal system. Magnetic characterization revealed that the field cooling curves of FeSi0.5Ge0.5 showed several magnetic transitions near 10 K, 100 K, and 140 K. In addition, FeSi0.5Ge0.5 and FeSi0.25Ge0.75 exhibited the characteristics of a disconnected magnetic phase at certain temperature points. The splitting magnetic phase in FeSi1−xGex is related to the atom-site distortion caused by Ge doping, demonstrating that in addition to the application of a magnetic field, the magnetic phase could be easily switched "on" and "off" by several critical temperatures. [ABSTRACT FROM AUTHOR]

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The Mg-doped VO2(B) nanorods were prepared by solvothermal and further heat treatment method. The effects of Mg doping on the structure, surface morphology, microdefects and electrochemical performances of the samples were comparatively investigated. The prepared samples were well crystallized in monoclinic structure, yet nonetheless there was a slight lattice expansion caused by Mg doping in the Mg-doped VO2(B) nanorods. With the increase of Mg doping concentration x (0.000, 0.005, 0.015, 0.030), the average grain size of the samples firstly decreased and then increased, and the grain size was the smallest when x was 0.015. Positron annihilation lifetime measurements revealed that there were vacancy-type defects in all the samples. The defect concentration and size in the Mg-doped VO2(B) samples were affected by Mg doping contents. The moderate amount of Mg doping can improve the structural stability and cycling performance of the samples. The Mg-doped VO2(B) sample with x = 0.015 showed the better cycling performance, which provided great potential applications in the electrode material of storage batteries. [ABSTRACT FROM AUTHOR]

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High performance lead‐free piezoelectric ceramics are of great importance to the sustainable development of the environment. To obtain excellent comprehensive performance KNN‐based lead‐free piezoelectric ceramics, a lattice distortion strategy combined with domain configuration was designed in (1 − x)K0.5Na0.5Nb0.95Sb0.05O3–xCaHfO3 ((1 − x)KNNS–xCH) system by introduced Ca2+ into the A‐site and Hf4+ into the B‐site. The results demonstrated that the rhombohedral–orthorhombic–tetragonal polymorphic phase boundary (PPB) was constructed in 0.02 ≤ x ≤ 0.04 and significant lattice distortion occurred in R‐ and T‐phase. Moreover, the 0.97KNNS–0.03CH sample exhibited excellent electrical performance (e.g., kp ∼ 43.8%, d*33 ∼ 478.6 pm/V, and d33 ∼ 392 pC/N) together with a high Curie temperature (TC ∼ 295°C) profited from the PPB and domain configurations. The ceramics also showed the optimal thermal stability, which was beneficial to promote the development of KNN‐based ceramics. [ABSTRACT FROM AUTHOR]