Modification Of Crystal Structure Research Articles

Radiofrequency affects the decrystallization efficiency and physicochemical properties of rape honey via crystal structure modification and inactivating enzyme

Crystallization degrades the physicochemical properties of honey and reduces consumer acceptance. To address this issue, radiofrequency was developed to investigate the decrystallization efficiency and quality impact mechanism of rape honey. The results showed that radiofrequency significantly decreased the number and size of crystals, leading to shortening the decrystallization time to less than 10 min. The response surface optimization methodology further indicated that the highest decrystallization rate (98.72 ± 0.34 %) and lower 5-Hydroxymethylfurfural (2.45 ± 0.12 mg/kg) contents were obtained. Furthermore, radiofrequency changed the honey from a pseudoplastic into a Newtonian fluid efficiently due to the volumetric heating feature. It is worth noting that the inactivation of glucose oxidase reduced the antibacterial capacity, while the increase in total phenolic and flavonoid contents improved the antioxidant capacity of rape honey. In summary, current findings indicated that radiofrequency is a potential alternative decrystallization technology for water baths.

In-Situ Raman Spectroscopy of Li+ and Na+ Storage in Anodic Nanotubes

Anodizing is a high-voltage electrochemical conversion process that forms barrier-type oxide layers or self-organized nanoporous/nanotubular structures. So far, the Al2O3-like nanopores and TiO2-like nanotubes could be successfully synthesized on many valve metals and alloys.Recently, it become possible to form nanotubular structures on iron and consequently control the ratio of hematite (Fe2O3) to magnetite (Fe3O4) by subsequent thermal treatment.1 Electrochemically active nanotubes, such as self-organized TiO2 are of high interest in the battery field due to a unique one-dimensional (1D) geometry offering high volume expansion tolerance and applications without binders and conductive additives. Herein, we report an in - situ Raman spectroscopy study under current control for a better fundamental understanding of Li+/Na+ storage in nanotubes and correlate the structural fingerprints with the electrochemical data on differential capacity plots of d(Q–Q 0) dE –1.2 Real-time measurements revealed that the nanotubes had undergone two major phase transformations with increasing lithium content, disclosing the sequential steps of a lithium intercalation type of storage. In contrast, sodium-ion insertion induced no significant crystal structure modification but instead a slight crystallinity rupture, signifying a dominant nondiffusion-limited capacitive type of storage. The insight into the charge storage in a 1D material in relation to other nanostructures such as nanoparticles3 will be discussed.1. L. Fadillah, D. Kowalski, M. Vincent, C. Zhu, S. Kitano, Y. Aoki and H. Habazaki, ACS Applied Materials & Interfaces , 2023, 15, 52563-52570.2. M. Vincent and D. Kowalski, ACS Applied Nano Materials , 2023, 6, 6528-6537.3. M. Vincent, S. S. Kumar and D. Kowalski, Electrochimica Acta , 2023, 469, 143161. Figure 1

Oxygen-defect rich SnO2-based homogenous composites for fast response and recovery hydrogen sensor

As a kind of green energy, hydrogen (H2) has been widely concerned and applied by people. One of the biggest challenges for sensing applications is the quick detection of hydrogen leaks or their release in various conditions, particularly in large electric vehicle batteries. This study successfully constructed a quick response and recovery hydrogen sensor based on the In2O3-SnO2 heterojunction. The response and recovery time of the In2O3-SnO2 hydrogen sensor is 1.1/1.9 s to 50 ppm H2. This is reduced to 11.0 %/9.5 % compared to the SnO2 hydrogen sensor. This sensor's remarkable gas detecting properties are mainly attributed to the In2O3-SnO2 heterojunction creation, crystal structure modification, and increased specific surface area (92.9 m2/g). Homogenous In2O3-SnO2 nanocomposites contain more oxygen defects, which is the primary factor enhancing the sensor's ability to detect gases. Firstly, indium ions are incorporated in the lattice of SnO2 results in lattice distortion and enhances the presence of oxygen deficiency in the composites, which plays a pivotal role in achieving rapid response and recovery of the sensor. Secondly, In2O3-SnO2 heterostructures promote rapid adsorption of oxygen molecules and target gases by facilitating effective electron mobility on their surface. The quicker response and recovery times of hydrogen sensors based on In2O3-SnO2 heterojunctions are observed. This innovative approach to creating fast-responding gas sensors highlights the promise of heterojunction-based hydrogen sensors for real-time H2 monitoring and opens up new research directions.

Nb/Mn co‐doping enhances the pyroelectric properties of Na0.5Bi4.5Ti4O15 ceramics for infrared detection

AbstractThe pyroelectric effect has wide applications in various fields, such as infrared imaging, detection, alarms, and the expanding field of smart homes. The rapid advancement of smart systems, focusing on miniaturization and integration, requires pyroelectric infrared detectors with high pyroelectric coefficients and Curie temperatures to meet the requirements of integrated processes. However, the Curie temperature of commercial lead zirconate titanate is limited to <230°C, urgently looking for a breakthrough. Here, we explore pyroelectricity in Na0.5Bi4.5Ti4O15 (NBT) ceramics, characterized by a high Curie temperature (∼660°C). We systematically examined the crystal structure modifications and defect dipole effects of the Nb/Mn‐co‐doped NBT. The lattice expansion, distortion of the TiO6 octahedra, and structural transformation tendency from the orthorhombic to tetragonal phase facilitate dipole movements with increasing temperature. Furthermore, the Mn and Nb elements result in the formation of MnTi“–VO·· and NbTi·–MnTi” –NbTi· defect dipoles, inducing additional polarization changes in response to temperature variations. Finally, a significantly improved pyroelectric coefficient of 110 µC m2 K–1 and remarkable temperature stability from 25°C to 300°C is achieved in NBTM‐5Nb ceramics. This co‐doping strategy for enhancing pyroelectric performance can be expanded to other systems and substantially contribute to advancing high‐performance materials for infrared detection.

Crystal Structure Modification and Dielectric Properties of Sr- and La-Containing A2B2O7 Thin Films for High-Temperature Operational Film Capacitors.

In order to obtain thermally stable thin-film materials with high dielectric constant, A2B2O7 thin films (Sr2Ta2O7, Sr2Nb2O7, La2Zr2O7, and La2Ti2O7) containing Sr or La and their solid solutions were grown on Pt/Ti/SiO2/Si substrates by RF sputtering and their crystal structures and dielectric properties were investigated. The Sr2Ta2O7 and La2Ti2O7 films exhibit highly oriented crystal structures. By contrast, the Sr2Nb2O7 and La2Zr2O7 films exhibit polycrystalline structures. The leakage properties of the Sr-containing films are lower and more stable in the high-temperature region (up to 300 °C) than those of the La-containing films. Among the investigated films, the Sr2Ta2O7 film grown at 500 °C and annealed at 900 °C shows the most stable dielectric constant with respect to temperature in the temperature range from room temperature to 300 °C. In addition, the xSr2Ta2O7-(1-x)La2Ti2O7 solid solutions exhibit enhanced dielectric properties at x = 0.35. The dielectric constant is greater than 100, and its variation with temperature is less than 10%. The Sr-containing A2B2O7 ferroelectric thin films have potential applications as high-temperature film capacitors that can operate at temperatures as high as 300 °C.

Carbon-coated TiNb2O7 microspheres with partial nitridation for high-performance lithium storage

TiNb2O7 has been applied to lithium-ion batteries owing to its large capacity and inherent safety, but suffers from its poor rate capability. Here, TiNb2O7 is modified through a combination of crystal-structure modification and conductive-phase coating, and C–NH3–TiNb2O7 with Ti2Nb[Formula: see text]O[Formula: see text]-type TiNb2O7 and Ti[Formula: see text][Formula: see text]Nb[Formula: see text]N/carbon double coatings is successfully synthesized. The unique Ti2Nb[Formula: see text]O[Formula: see text]-type structure of TiNb2O7 owns a large interlayer spacing, leading to fast Li[Formula: see text] diffusivity and remarkable intercalation-pseudocapacitive behavior. The conductive Ti[Formula: see text][Formula: see text]Nb[Formula: see text]N/carbon coatings result in good electrical conduction among the TiNb2O7 microspheres. Consequently, C–NH3–TiNb2O7exhibits excellent rate capability of TiNb2O7 (large capacity percentage of 73.9% at 5C versus 0.5C). Besides the fast electrochemical kinetics, C–NH3–TiNb2O7 further exhibits large reversible capacities (237 mAh g[Formula: see text]at 0.1C and 146 mAh g[Formula: see text]at 5C) and outstanding cyclability (93.1% capacity retention after 500 cycles at 5C). These desirable electrochemical properties fully demonstrate that the C–NH3–TiNb2O7 anode material can be suitable for high-performance Li[Formula: see text]-storage.

Effect of carboxymethyl chitosan on the storage stability of rice dough during frozen storage

In this study, we aimed to determine the effect of carboxymethyl chitosan (CMCh) and carboxymethyl cellulose sodium (CMCNa) on the quality of frozen rice dough. We used a variety of methods to conduct a thorough investigation of frozen rice dough, including nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, size exclusion high-performance liquid chromatography (SE-HPLC), X-ray diffraction (X-RD), differential scanning calorimetry (DSC), and rapid visco analyzer (RVA). Our findings showed that frozen storage caused significant damage to the texture of rice dough, and this damage was reduced by the inclusion of CMCh, which led to a gradual change in the orderly structure of proteins. The degree of cross-linking between CMCh-B (DS:1; 0.5 %, 1 %, and 1.5 %) and the large protein polymer was significantly higher than that between CMCh-A (DS:0.8; 0.5 %, 1 %, and 1.5 %) and CMCNa (DS:1; 1 %), which decreased the ability of bound water to become free water. This resulted in the increase of tan δ, which effectively delayed the structural transformation of frozen rice dough. Furthermore, the introduction of CMCh delayed the immediate order of starch and crystal structure modifications, altering the thermal properties and pasting qualities of the frozen rice dough. Therefore, 1.5 % CMCh-B showed the best protective effect on frozen rice dough.

Direct Photocatalytic Methane Oxidation to Formaldehyde by N Doping Co-Decorated Mixed Crystal TiO2.

In this paper, N-doped TiO2 mixed crystals are prepared via direct calcination of TiN for highly selective oxidation of CH4 to HCHO at room temperature. The structures of the prepared TiO2 samples are characterized to be N-doped TiO2 of anatase and rutile mixed crystals. The crystal structures of TiO2 samples are determined by XRD spectra and Raman spectra, while N doping is demonstrated by TEM mapping, ONH inorganic element analysis, and high-resolution XPS results. Significantly, the production rate of HCHO is as high as 23.5 mmol·g-1·h-1 with a selectivity over 90%. Mechanism studies reveal that H2O is the main oxygen source and acts through the formation of ·OH. DFT calculations indicate that the construction of a mixed crystal structure and N-doping modification mainly act by increasing the adsorption capacity of H2O. An efficient photocatalyst was prepared by us to convert CH4 to HCHO with high yield and selectivity, greatly promoting the development of the photocatalytic CH4 conversion study.

High content pyridine nitrogen-doped carbon nanosheets derived from ZIF-L as anode materials of lithium-ion batteries with excellent capacity and rate performance

The precise control of nitrogen doping types in carbon materials is crucial for optimizing energy storage devices. In this study, we synthesize nitrogen-doped carbon nanosheets (NCS) using ZIF-L as a precursor. Comparatively, the two-dimensional crystal structure of ZIF-L provides several advantages over ZIF-8 as a precursor in terms of nitrogen doping efficiency, achieving a higher doping level (14.56 %) and an increased ratio of pyridinic nitrogen (53.60 %). Consequently, NCS display a greater capacity for pseudocapacitive lithium storage. Furthermore, by adjusting the carbonization temperature, we precisely tailor the graphite-nitrogen doping level of NCS within the range of 16.80–31.22 %. Remarkably, when employed as an anode material in lithium-ion batteries, NCS-800 demonstrates exceptional cycling stability, with a capacity retention of 1078 mAh g−1 after 500 cycles at a current density of 0.5 A g−1, as well as excellent rate capability (735 mAh g−1 at 5 A g−1). This study not only compares the impact of precursor crystal structure modifications on nitrogen doping and lithium storage performance but also introduces a novel synthesis methodology for highly nitrogen-doped carbon materials, offering new avenues for future research in this field.

Assessment of the catalytic and biological potential of yttrium and samarium-modified copper ferrite nanomaterials

The present study reports the preparation of crystalline and nanosized copper ferrite (CuFe2O4), Y3+ substituted CuFe2O4 (CuFe1.95Y0.05O4), and Sm3+ substituted CuFe2O4 (CuFe1.95Sm0.05O4) using a simple co-precipitation method. The XRD analysis confirmed the formation of the cubic spinel phase, while XPS studies validated the presence of Cu and Fe in 2+ and 3+ oxidation states respectively. Transmission electron microscopy (TEM) analysis revealed the nanoparticles with a diameter in the range of 10–60 nm. The introduction of fractional amounts of Y3+ and Sm3+ ions in the CuFe2O4 lattice enhanced the reduction of 4-nitrophenol, attributed to decreased particle size facilitating the reduction process. In the case of antimicrobial activity, Candida albican was found to be maximally sensitive to CuFe2O4 and CuFe1.95Y0.05O4, while Pseudomonas aeruginosa was inhibited by CuFe1.95Sm0.05O4. Moreover, a maximum of 61.9 ± 1.91 % anti-Pseudomonas biofilm activity and 75.7 ± 1.28 % DPPH radical scavenging activity was observed for CuFe1.95Y0.05O4 at 200 μg/ml concentration. The improvement in biological activities was attributed to the reduced particle size, crystal structure modification, and increased stability of the CuFe2O4 lattice with substitution. The enhancement in catalytic and biological performance highlighted the effectiveness of minimal Y3+ and Sm3+ concentrations in modulating the properties of CuFe2O4 nanomaterials.

Effect of La3+and Al3+ doping on the crystal structure and magnetic properties of strontium hexaferrites

Modification of crystal structure and magnetic properties of M-type strontium hexaferrites (SrM) doped with foreign ions (Al3+, La3+) was studied, focusing on the distortion of the lattice. Incorporation of Al3+ ions contracted the lattice of SrM and hardened lattice vibration modes with lattice disorders. X-ray diffraction examined the lattice distortion of FeO5 trigonal bipyramidal sites (TBP) revealing that off-center displacement (z0) was reduced to z0 = 0 by heavy Al3+ doping. This reduction of z0 was attributed to stabilization of single-well potential in the positioning of Fe3+ ions in TBP. Furthermore, La3+ doping led to a more significant contraction of the lattice and restored a non-zero off-center displacement of Fe3+ ion in TBP. The polycrystalline ceramics with high coercivity exceeding 21 kOe through the conventional ceramic processing route with concomitant La3+ and Al3+ doping.

DFT calculations of the structural, elastic, and electronic properties of (Bi1−xFex)2Te3 chalcogenides

The crystal structure and elastic and electronic properties of (Bi1−xFex)2Te3 were studied by first-principles calculations within the Density Functional Theory (DFT) scheme. We found that at zero GPa, the lattice parameters for Bi2Te3 are in good agreement with the available experimental and theoretical data. As Fe replaces bismuth, the lattice parameter a increases while c decreases, changing the unit cell volume. According to Born’s structural stability criterion, the system is mechanically stable. Poisson’s ratio suggests a change from brittle to ductile behavior for (Bi1−xFex)2Te3 as iron increases. Also, Poisson’s ratio indicates that there is an ionic-covalent bond for x = 0.00 and behave as a metal as iron content increases. Vickers hardness decreases its value as Fe is introduced in the compound. Band structure calculations show that the results with spin orbit coupling (SOC) and without SOC are in good agreement with the experimental results. With SOC, a direct band gap at the Γ point is obtained with Eg = 0.138 eV concerning the 0.226 eV obtained without SOC. An evident modification of crystal structure in (Bi1−xFex)2Te3 shows a consistent trend, indicating a significant impact of iron incorporation on the structural properties. The electronic properties show a significant transformation with the introduction of iron, Bi2Te3 is characterized by a band gap, through iron doping the electronic structure shows a complete elimination of the band gap, marking a transition from semiconductor towards a conductor-like behavior. Density of states analysis provided insight into these changes, illustrating a modulation of electronic properties dependent on iron content.

Inquire into Co-doped pyrite crystal structure modifications and implications for flotation behavior: A DFT study

Cobalt (Co), as a vital strategic resource, is applied widely in battery materials and alloy manufacturing. In minerals, Co is often doped into pyrite by lattice substitution. Co-doped pyrite is typically enriched by froth flotation. However, research on the flotation mechanisms of Co-doped pyrite is limited. Density functional theory was used to investigate the influence of Co doping on the crystal structure of pyrite. The difference in the hydrophobicity and collector adsorption of Co doping in pyrite was discussed. Co replaces Fe in pyrite through lattice substitution to form Co-pyrite. Co-doped pyrite shows increased conductivity and decreased covalent bonding nature of Co-S bonds compared with pyrite. Co doping enhances the surface hydrophobicity of pyrite. The electron transfer between butyl xanthate (BX) and Co-doped pyrite is more intense than that of pyrite. BX mainly interacts with the Co 3d orbitals of Co-doped pyrite through the S 3p orbitals. The interaction mode is bonding, and orbital hybridization occurs. Moreover, BX exhibits more stable adsorption on the surface of Co-doped pyrite than that on pyrite. The presence of water molecules has a minor promotional effect on the adsorption of BX.

Modeling carbon dioxide and methane adsorption on illite and calcite: enhancing the simplified local density model through crystal structure modifications.

The simplified local density (SLD) model has been frequently utilized to describe gas adsorption in porous media. The common assumptions associated with the SLD model are the graphene slit and uniform distribution of atoms. However, these fail to depict the heterogeneous surface of minerals. In this study, the original SLD model was modified by substituting mineral crystal structures for the homogeneous carbon layer when building the slit. The modified model may capture the heterogeneity-induced variation of the fluid-pore interaction potential and adsorbed phase density near the mineral surface. The calculated adsorption isotherms of methane and carbon dioxide on illite and calcite surfaces at 330.15 K were compared with literature experiment data to validate the modified SLD model. For the simulation of gas adsorption isotherms, the modified model predictions agree reasonably well with the previously reported experiment results using the gravimetric method. The calculated density profile in the slit indicates the monolayer adsorption behavior of CH4 and CO2. Based on more precise interaction potentials, the number of regression parameters was reduced to two, and the physical meaning of the model parameters was clarified. Therefore, for estimating hydrocarbon storage in reservoirs, the modified SLD model could be used as an efficient alternative to time-consuming molecular simulation methods.

Crystal structure modification of nano-hydroxyapatite using organic modifiers and hydrothermal technique.

Hydroxyapatite (HAp) synthesis was achieved through a hydrothermal method involving orthophosphoric acid and calcium hydroxide. Different organic modifiers such as urea, naphthalene, and palmitic acid were applied in the reaction system to modify the crystallite size along with the morphology of HAp. The synthesized HAp was validated via X-ray diffraction (XRD) data, Fourier Transform Infrared (FTIR) spectra, Field Emission Scanning Electron Microscopy (FESEM) image, and optical bandgap energy (<6 eV) was determined through UV-vis spectrophotometry. Apart from that, different techniques such as Scherrer's method, Halder-Wagner model, Williamson-Hall method, size-strain plot, as well as Sahadat-Scherrrer's models were applied for calculating the crystal domain size, and some models also incorporated energy density, strain, and stress. The synthesized HAp has a crystal structure that falls within the permissible range of <100 nm, as established by analyzing the XRD data using established models. Nevertheless, the values for strain (from -0.0006 to 0.0062), stress (from -30 902 to 36 940 N m-2), as well as energy density (from 4 × 10-14 to 113.72 J m-3) were likewise computed for the synthesized HAp. The texture co-efficient analysis reveals that doped HAp is grown in the (202) and (112) planes, palmitic acid_HAp in (002), (112), and (202) planes, while all the synthesized HAp (pure HAp, urea, naphthalene) is grown in the (002) and (112) planes. Rietveld refinement was also performed to estimate the quantative phase percentage from XRD data.

Enhanced bioaccessibility of curcumin in Pickering emulsions stabilized by solid lipid particles

To investigate curcumin release behavior of Pickering emulsions (PEs) with controlled crystal polymorphism, solid lipid particles (SLPs) were fabricated using Tween 40 (T40-SLPs) or sodium caseinate (SC-SLPs) at 4 °C or 25 °C. T40-SLPs were characterized as β crystal (100%) at 25 °C, and co-crystallization of Tween 40 (2 % by weight (wt.%) vs. 4 wt%) induced formation of β crystals (24.86% vs. 52.88%) at 4 °C. SC-SLPs solely contained α crystals at 4 °C, and addition of sodium caseinate (2 wt% vs. 4 wt%) reduced content of β crystals (7.55% vs. 2.82%) at 25 °C. The indigestibility of β crystals differentiated interfacial digestive behavior of SLPs. PEs stabilized by SC-SLPs underwent more aggregation and released more curcumin upon exposure to pepsin and mucin. High content of β crystals in SC-SLPs enhanced curcumin bioaccessibility in simulated intestinal digestion, whereas high SC concentrations induced undigested SC self-assembled with β crystals, reducing the curcumin bioaccessibility. PEs stabilized by T40-SLPs showed better-targeted delivery, with higher FFA release and curcumin bioaccessibility during in vitro intestinal digestion. Co-crystallization of T40 enriched β crystals in T40-SLPs but reduced the release and bioaccessibility of curcumin. Hence, surface modification of fat crystals and crystal structure determines bioaccessibility of curcumin in PEs stabilized by SLPs.

Etching Strategy for Photocatalysis: The Evolution of Structures and Properties

This review emphasizes the pivotal role of etching strategies in refining structures and properties crucial to photocatalysis, a sustainable solution for energy and environmental remediation. As fossil fuel‐related environmental concerns rise, photocatalysis emerges as a vital alternative. Yet, maximizing its efficacy is an ongoing challenge. Etching strategies, by creating structural vacancies and revealing active crystal facets, enhance light absorption and the catalyst's efficiency. This process effectively reshapes nanostructures, elevating their surface specificity and subsequently their catalytic properties. Despite advancements, few comprehensive reviews detail etching's influence on photocatalysts. This work, therefore, sheds light on how different etching methodologies affect photocatalyst structures and functions, covering mechanisms such as morphology control, surface area boosting, defect engineering, and more. Furthermore, the impact of etching on light absorption, charge dynamics, and reactant interactions is explored. The review concludes by pointing out challenges and the prospective growth of etching in photocatalysis. By deepening the understanding of etching modification, this review aims to drive progress in developing superior photocatalytic materials, thus fostering advances in renewable energy technologies.

Effects of Gd3+ substitution on the structure, photoluminescence, scintillation, and thermometric features of Pr3+:Lu2Zr2O7 phosphors

AbstractIn this study, it is shown how the photoluminescence, scintillation, and optical thermometric properties are managed via the introduction of Gd3+ ions into Pr3+:Lu2Zr2O7. Raman spectra validate that partial replacement of Lu3+ with Gd3+ can promote the phase transition of Lu2Zr2O7 host from the defective fluorite structure to the ordered pyrochlore one. Upon 289 nm excitation, all the samples emit the 483 (3P0 → 3H4), 581 (1D2 → 3H4), 611 (3P0 → 3H6), 636 (3P0 → 3F2), and 714 nm (3P0 → 3F4) emissions from Pr3+ ions, which are enhanced with the addition of Gd3+ ions due to the modification of crystal structure. Dissimilarly, the X‐ray excited luminescence spectra consist of a strong emission located at 314 nm from Gd3+ ions (6P7/2 → 8S7/2), together with the typical emissions from Pr3+ ions, which exhibit different dependences on the Gd3+ concentration. When the luminescence intensity ratio between the 3P0 → 3H6 (611 nm) and 1D2 → 3H4 (581 nm) transitions is selected for temperature sensing, Pr3+:(Lu0.75Gd0.25)2Zr2O7 shows the optimal relative sensing sensitivity of 0.78% K−1 at 303 K, which is higher than that of the Gd3+‐free sample. Therefore, the developed Pr3+:(Lu, Gd)2Zr2O7 phosphors have the applicative potential for optical thermometry, X‐ray detection, and photodynamic therapy.

X-Ray Structural Investigations Of n-Si&lt;Pt&gt; Irradiated with Protons

In this work, the effect of proton irradiation on the change in the structure of silicon samples doped with platinum was studied. The samples were irradiated with protons at a dose of 9×1014 cm-2 with an energy of 600 keV and a current of 1÷1.5 μA. To determine the change in the structure after irradiation, the methods of X-ray diffraction and atomic force microscopy were used. The obtained results indicate that doping with platinum does not lead to a modification of the cubic crystal structure of silicon, but only to minor changes in the structural characteristics and surface morphology. In this case, proton irradiation of a silicon single crystal with a dose of 9.0×1014 cm–2 with an energy of 600 keV leads to the formation of defects without the formation of an amorphous near-surface layer.

Fluorosulfide La2+xSr1–xF4+xS2 with a Triple-Fluorite Layer Enabling Interstitial Fluoride-Ion Conduction

Fluoride-ion conducting solid materials are applicable as solid electrolytes for sensing devices and next-generation rechargeable batteries. Most of the previously reported materials have been limited to the single-anion compounds such as fluorite-type, tysonite-type, and perovskite-type structures. These suffered from further improvements by crystal structure modification which derives a paradigm shift in the material tailoring. Fluoride and sulfide ions prefer respective coordination environments because of the different ionic radii and electronegativity. This feature implies that fluorosulfide mixed-anion compounds have potential to form anion-ordering crystal structures with new fluoride-ion conducting layers. Herein, we have found that the fluorosulfide La2+xSr1–xF4+xS2 exhibits fluoride-ion conduction. The presence of multiple anions results in the formation of an anion-ordering two-dimensional crystal lattice with triple fluorite layers, which cannot be realized for metal fluorides. Sulfide ions in the crystal structure increase the number of interstitial sites of fluoride ions, forming a fluoride-ion conduction pathway.