Abstract The porous and mixed ionic electronic cathode conductor plays a vital role in the efficient working of low‐temperature solid oxide fuel cells. Perovskite composite cathode material La0.3Sr0.7Fe0.4Ti0.6O3‐δ (LSFT) is synthesized using the sol–gel method. Graphene oxide (GO) is integrated in 1 and 1.5 wt.% into the perovskite LSFT cathode to use as a cathode for low‐temperature solid oxide fuel cell (LT‐SOFC). Crystal structure analysis is studied by XRD and the crystalline size of samples is determined in the range of 103–73 nm. SEM analysis is used to characterize homogeneous and porous morphology. The FTIR spectral analysis is examined for proposed nanocomposite cathode materials. The electrical conductivities are carried out by four probe method in air atmosphere in the temperature range 300–600 °C and enhanced conductivity is obtained 7 Scm−1 for LSFT‐1.5 wt.% GO sample. For the same sample, a minimum value of area‐specific resistance (ASR) of 0.02 Ωcm2 is obtained. The performance of three‐layer fuel cells is tested by supplying H2 fueled at the anode and oxygen at the cathode terminal of the cell and peak power density is determined to be 362 mWcm−2 for GO incorporated fuel cell. The prepared cathode can be proposed as a potential candidate for low‐temperature solid oxide fuel cells.

Abstract The structure and space‐group symmetry of modular structures can be obtained from the knowledge of the structure and subperiodic symmetry of the modules and of the structure‐building operations. This leads to a space groupoid, which contains all the partial operations relating any pairs of modules. Those partial operations that possess a continuation in the whole crystal space are global operations that show up in the space group of the structure. The whole procedure is presented through the example of pyroxenes. The modular structure of these minerals has already been analyzed in the past, but the groupoid construction has only been synthetically described. In this paper, the full step‐by‐step process is presented, which is largely unknown in the crystallographic community.

Abstract At present, the problem of environmental pollution is becoming increasingly serious. It is urgent to develop efficient catalysts to solve these problems. To obtain the functional characteristics of CaCO3 and promote its application in coatings and photo‐catalysis, ZnO/CaCO3 particles are prepared by the solution co‐precipitation method under the mediate of sodium dodecyl sulfate (SDS) through corresponding strategies. The structures and morphologies of samples are characterized by XRD, FT‐IR, SEM, and TEM, respectively. Besides that, the photo‐catalytic property of the desired product is also evaluated. The results indicate that SDS helps to induce the formation of porous structure. Through co‐precipitation, ZnO particles uniformly load on porous calcium carbonate. ZnO/CaCO3 particles are endowed with low‐cost property and high catalytic performance under the synergistic effect of photo‐catalytic properties and absorption abilities. This work established a simple way to produce the composite catalysts with low price and high photo‐catalytic activity.

Abstract The addition of 8 mol% of Y2O3 to the ZrO2@mullite composites stabilizes the metastable tetragonal phase of ZrO2 in conventional and plasma‐sintered Y2O3‐stabilized ZrO2@mullite composites. A fused, highly dense, and interconnected microstructure is formed in the case of plasma‐sintered Y2O3 stabilized ZrO2@mullite composite. At 1 MHz frequency, the room temperature and tanδ of (10.37 and 2.06) is obtained for the conventional Y2O3 stabilized ZrO2@mullite composite and that of (38.8 and 4.02) is observed for the plasma sintered Y2O3 stabilized ZrO2@mullite composite. The substitution of Y3+ in place of Zr4+ creates sufficiently large oxygen vacancies at the grain boundary regions of these composites endowed mostly with the ZrO2 phase. In conventional Y2O3‐ ZrO2@mullite composites, both dielectric relaxation as well as conductivity relaxation are observed due to the dynamic motion of dipoles and relaxation due to the presence of defect states and porous structures. This leads to higher grain boundary conductivity than the grain conductivity of these composites. Thermally activated conduction mechanisms exhibited in these composite materials are projected from the complex impedance and modulus analysis. The conventional and plasma sintered Y2O3‐ ZrO2@mullite composite has an optical bandgap of 3.26 and 3.58 eV, respectively.

Abstract Large single crystals of polar tetragonal thallium antimony(III) tartrate dihydrate, Tl2[Sb2((+)C4H2O6)2]·2H2O, are grown. The crystal structure (s.g. P41), which contains the binuclear complex group [Sb2(C4H2O6)2]2− and dimer groups [Tl2O8(H2O)2], is given, together with vibrational spectra, refractive indices and their dispersion, and an analysis of SHG phase matching possibility and SHG powder measurements. The crystals allow type I phase matching for laser wavelengths ≥ 1.0103 µm. In addition, a new monoclinic (s.g. C2) antimony(III) tartrate of composition Mg[Sb3((+)C4H2O6)2((+)C4H4O6)((+)C4H5O6)]·11H2O and its crystal structure, which contains a novel type of antimony tartrate complex group [Sb3(C4H2O6)2(C4H4O6)(C4H5O6)], is presented.

Abstract Present work reports on the synthesis of spike‐shaped Zirconia nanoparticles (S‐Zr NPs) by a simple co‐precipitation method for supercapacitors. Physico‐chemical properties viz. structural and morphological features of as‐synthesized S‐Zr NPs are confirmed by Fourier transform infrared (FTIR), Ultraviolet‐Visible (UV–Vis), photoluminescence (PL), Raman,X‐ray diffraction (XRD), and Field emmision scanning electron microscopy (FESEM) analysis. As‐synthesized S‐Zr NPs have an average length and diameter of below 250 and 50 nm, respectively. Rietveld analysis is also performed that reveals the presence of the monoclinic phase as the major phase (99.67%) along with the tetragonal phase. Electrochemical performance is measured by cyclic voltammetry, charge–discharge profile, and impedance spectroscopy. S‐Zr NPs exhibit the maximum specific capacitance of 108.88 F g−1 at 1 A g−1 in 1 M aq. KCl solution.

Abstract Using first‐principles density‐functional theory (DFT), this study thoroughly investigates the effects of biaxial and uniaxial tensile strains on the electronic, optical, and thermoelectric properties of the perovskite ScBiTe3. This latter compound is a semiconductor material, according to its electronic band structures, with an indirect bandgap value of 0.891 eV. Additionally, the bandgap of each structure exhibits a decreasing tendency under compressive strain and an increasing trend under tensile strain, and the bandgap changes from indirect to direct bandgap when the tensile strain is applied along the a and b directions. Due to their band properties, these materials have excellent absorption ability in the visible region, as evidenced by optical properties like dielectric functions, absorption coefficients, and electron loss functions. It is found that the highest value of the power factor (PF) is 4.1 × 1011 W−1K−2s−1 and the highest value of the figure of merit (ZT) is 0.84. Such values are obtained for the specific strain value of 10% strain along the “a” and “b” directions. This confirms that this material can be a potential candidate for thermoelectric device applications.

Abstract Boric acid is widely used in human life and industrial production. However, few methods for solving the slow dissolution behavior of boric acid are reported. Based on the Density Functional Theory (DFT) analysis, a reasonable modulation strategy is proposed and an effective regulation method is obtained for preparing instant boric acid in this work. The DFT theoretical calculations and various characterizations explain the relation between the exposed surface of crystalline boric acid and its dissolution rate. The experiment results prove that the slow dissolution behavior of boric acid can be dramatically improved by regulating its exposed surface of crystalline particles. This work may fill the lack in the controllable regulation of boric acid crystalline structure and provide new perspectives for improving the dissolution rate of other crystalline products.

Abstract In this study, the anisotropic mechanical properties of YAG crystal (100), (110), and (111) crystal faces are investigated by nanoindentation experiments. The load‐displacement curves, hardness (H) and elastic modulus (E) are obtained for each crystal face at different maximum loads. The loading curves of the three crystal faces showed displacement mutations, which are caused by microcracks during indentation of the indenter. The H and E of three crystal faces dropped as the indentation depth increased, obviously indicating indentation size effect (ISE). The H and E magnitude sequence of the three crystal faces is: (110) > (111) > (100). The surface energy is calculated by the Cambridge Serial Total Energy Package (CASTEP) program to explain the experimental phenomenon that the hardness and elastic modulus of the three crystal faces are different. Using the Nix‐Gao model to fit the Hardness‐indentation depth data, the hardness H0 of the (100), (110), and (111) crystal faces without strain gradient effect are obtained as 12.978, 15.61, and 15.432 GPa, respectively, which can be used as a reference value for the hardness of YAG crystals. The characteristic lengths h* of (100), (110), and (111) crystal faces are 730.545, 362.049, and 375.196 nm, respectively.