Microelectronic printing meets the demand for patterned or large-area perovskite films and, given its low cost, holds distinct advantages in industrial production. However, the crystallinity of printed perovskite films is generally relatively inferior, especially to that of spin-coated films. Under this drive, a "self-induced heterogeneous nucleation growth" scheme is developed to orchestrate the crystallization kinetics of printed quasi-2D hybrid-halide perovskite films. In this scheme, uniformly dispersed clusters with perovskite-like structures that derive from low-cost custom-built microcrystals as the crystal nucleus establish a distinct nucleation pathway that bypasses the need for both foreign particles and high energy to nucleate, directly enabling the rapid and orderly growth of printed perovskite films. This tailored crystalline growth simultaneously induces a preferentially oriented crystal phase distribution and an optimized dimensional phase arrangement, in which synergistic structural control promotes efficient carrier transport while effectively suppressing nonradiative recombination by restraining halogen segregation and defect generation during the crystallization fundamentally. Consequently, this ambient, additive-free, and scalable ink engineering motivates the establishment of a general and mature preparation framework for advancing printed perovskite optoelectronics, and the corresponding printed PEABr(MAPbI3) films achieve a remarkable PLQY of 46.35% at 650 nm, one of the highest photoluminescence efficiencies that has been reported.

The physicochemical properties of solid solutions [Ba1-xNax][Ti1-y-xZryNbx]O3 with varying concentrations of NaNbO3 (x = 0.02, 0.04) and BaZrO3 (y = 0.00, 0.05, 0.10) were investigated. The samples were synthesized via a two-stage solid-state reaction method with preliminary mechanoactivation. X-ray diffraction analysis revealed that all samples possess a perovskite-like structure with minor impurity phases. Increasing the Z4+ concentration leads to broadening of diffraction peaks and the appearance of diffusion maxima, this may indicate modulation effects and inhomogeneous cation distribution (Zr4+, Ti4+, Nb5+). The unit cell parameter monotonically increases from 4.009 to 4.037 Å as Zr4+ content rises from 0 mol. % to 10 mol. %. The relative density of the ceramics reaches a maximum of 88.50 % at y = 0.10. SEM analysis revealed an underdeveloped fine-grained microstructure (average grain size ≈ 2 μm) with pronounced porosity, attributed to low-melting eutectics forming a liquid phase during sintering. Studies of dielectric hysteresis loops demonstrate an increase in total energy density from 0.998 to 1.551 J/cm3, accompanied by a sharp decrease in energy efficiency from 56.1% to 10.8% with increasing Zr4+ content. The highest energy storage density is expected in the concentration range 0 ≤ y < 0.05. The obtained results can be applied to the development of lead-free ceramics based on BaTi(1-y)ZryO3.

In this work, we report the synthesis, crystal growth, and optical and magnetic properties of two new isotypic bimetallic thiocyanates, MnBi(SCN)5 and CdBi(SCN)5. The crystal structure of MnBi(SCN)5 and CdBi(SCN)5 was determined by single-crystal X-ray diffraction. MnBi(SCN)5 and CdBi(SCN)5 crystallize in the triclinic space group P1̄ (no. 2) with unit cell parameters of a = 8.0498(5) Å, b = 9.2749(5) Å, c = 10.7779(8) Å, α = 72.752(6)°, β = 68.422(6)°, γ = 87.908(5)° and a = 8.1528(5) Å, b = 9.4008(7) Å, c = 10.9513(8) Å, α = 73.212(6)°, β = 67.963(6)°, γ = 87.879(6)°, respectively. The structure of MnBi(SCN)5 and CdBi(SCN)5 contains a three-dimensional (3D) network consisting of pairs of edge-sharing [TN6] (T = Mn, Cd) octahedra linked through the thiocyanate ligand to similar pairs of edge-sharing [BiS6] octahedra. A known related structure to this is that of FeBi(SCN)6, which features a perovskite-like structure consisting of corner-sharing [FeN6] and [BiS6] octahedra. In this work, the magnetic properties of MnBi(SCN)5 and the previously reported FeBi(SCN)6 were investigated, with the former being found to order antiferromagnetically with a Néel temperature around 12 K. FeBi(SCN)6 was found to exhibit no magnetic ordering down to 2 K, although isothermal magnetization data indicate that it may order ferromagnetically below 2 K. Density functional theory (DFT) was also employed to explore the electronic structure of MnBi(SCN)5, which reveals that the Bi-S and Mn-N interactions are crucial for controlling the optical properties of MnBi(SCN)5. MnBi(SCN)5 was predicted to be an indirect-gap semiconductor with a bandgap of 2.7 eV, which was reasonably consistent with the UV-vis spectrum measurement of 2.1 eV.

Abstract Due to the light absorption properties of perovskites, including halides, perovskite cells are considered an ideal energy system. This study aims to improve photoexcitation separation by introducing a material with a perovskite-like structure, such as Cs3Bi2I9, alone or with barium titanate nanoparticles as a second choice, while the third choice is to impregnate barium titanate (prepared by hydrothermal method) with ZnO to form BaTiO3/ZnO, then mix it with Cs3Bi2I9. All these choices are fabricated as a sandwich between the n-type and p-type collection. The produced layers, BaTiO3/ZnO /Cs3Bi2I9, were characterized using XRD, EDX, SEM, and UV-Vis spectroscopic analytical techniques. The results suggest that the band gap of the prepared layer was further decreased compared to the original material, Cs3Bi2I9. The performance test revealed a photo conversion efficiency (PCE) of 3.13% and a highest power of 3.15 MW, comparable to or higher than other studies. This suggests that this layer significantly reduces recombination phenomena and improves the cell's performance overall.

The pursuit of devising efficacious methodologies for the creation of innovative and exceptional noncentrosymmetric (NCS) compounds has emerged as an urgent undertaking. Herein, the first guanidinium-containing niobium oxyfluoride, C(NH2)3NbOF4, possessing a perovskite-like structure, was synthesized via a mild hydrothermal method. The title compound crystallizes in the polar space group P4bm (No. 100), with unit cell dimensions as follows: a = 13.2479(9) Å, c = 3.9492(4) Å, V = 693.11(12) Å3, and Z = 4. Its structure is composed of planar π-conjugated cation [C(NH2)3]+ and second-order Jahn-Teller distorted octahedra [NbO2F4]3-. Combining experimental and theoretical calculations, we demonstrate that C(NH2)3NbOF4 exhibits a second-harmonic-generation (SHG) response, confirming its NCS structure, along with an impressive birefringence of 0.207 at 546 nm. Notably, the title compound demonstrates light-blue emission, suggesting its potential as a trifunctional optical material. Therefore, this study not only expands the structural diversity of transition-metal oxyfluorides but also promotes the discovery of new perovskite-like functional materials.

Organic–inorganic hybrid halide perovskites have attracted attention in optoelectronics and photovoltaics. However, the Pb-content in the crystal structure and instability issues have raised questions about the industrialization of these materials. Bi and Sb are widely considered as an alternative on the B-site due to their isoelectronic configuration with the Pb divalent cation. Herein, we report four novel Pb-free azetidinium metal halides and present their fundamental material properties: [(CH2)3NH2]2AgBiBr6, [(CH2)3NH2]3Bi2I9, [(CH2)3NH2]3Bi2Br9, and [(CH2)3NH2]3Bi2Cl9. Our materials have a low-dimensional perovskite-like structure from 0 to 2D, where the replacement on the B-site is based on Ag+/Bi3+ and Bi3+.Graphical As a potential light absorber, four different azetidinium metal halides were successfully synthesized via evaporation. The polycrystalline powders and thin films of the azetidinium metal halides present low dimensionalities from 0 to 2D.

Significant enhancement of piezoelectric properties by mechanochemical activation in perovskite-like layered structure La2Ti2O7 ceramics

Improving the energy storage density of dielectric capacitors, which are widely used in power electronic devices, is a continuous challenge. In this work, a site-selection multi-element co-doping strategy was used by doping Pr atoms at the A-site and then doping Mn atoms at the B-site in bismuth-based layered perovskite-like structure prototype ferroelectrics Bi4Ti3O12 due to its large polarization and high Curie temperature. On the one hand, the substitution of Bi3+ with Pr3+ at the A-site introduces significant cation disorder, which disrupts the long-range ferroelectric order, consequently leading to a reduction in remnant polarization. On the other hand, the substitution of Ti4+ by Mn4+ at the B-site results in delayed polarization saturation due to the different electronic configurations between d3 Mn4+ and d0 Ti4+. In addition, the leakage current of the thin film exhibits a continuous decrease with doping concentration, which can be attributed to microstructural modifications including reduced grain size and the formation of amorphous regions, consequently leading to an enhanced breakdown field. Finally, a recoverable energy storage density of 42.1 J cm−3 and an efficiency of 69.9% were obtained for the BPT film, and a recoverable energy storage density of 81.8 J cm−3 and an efficiency of 73% were achieved in the BPTM film. The enhanced energy storage density can be attributed to the synergistic effect of co-doping of A- and B-sites on polarization and breakdown. Besides, the doped films have excellent frequency, temperature, and cycling stability. This work provides a guide to substantially enhance dielectric energy storage by a site-selection multi-element co-doping strategy.

The co-substitution of neodymium (Nd) and iron (Fe) into CaSnO3 provides, for the first time, the double perovskite-like structure NdCaFeSnO6. A comprehensive investigation of the structural, microstructural, vibrational (Raman), optical and electrical properties of the resulting NdCaFeSnO6 compound, synthesized via a solid-state method, is reported. Elemental analysis using Energy-Dispersive X-ray spectroscopy (EDX) confirmed the successful incorporation of Nd, Fe, Ca, Sn and O. Semi-quantitative analysis results are consistent with the intended stoichiometry. X-ray diffraction (XRD) investigation revealed a monoclinic P21/c crystal structure, with a minor secondary phase. Rietveld refinement converges to satisfactory factors, indicating an equidistribution of Fe and Sn cations between the octahedral sites. Raman spectroscopy further characterized this symmetry, showing several bands associated with the bending and stretching modes of (Sn/Fe)O6 octahedra. Significant narrowing of the bandgap from 4.27 eV for the pristine CaSnO3 to 2.44 eV in NdCaFeSnO6 supports the presence of structural defects and oxygen vacancies within the (Nd/Ca)–(Fe/Sn)–O framework. The electrical properties were elucidated with emphasis on the ionic conduction mechanism in NdCaFeSnO6with charge carrier hopping at intermediate temperatures with an activation energy of 0.97 eV for grain boundaries and 0.31 eV for grains, based on impedance spectroscopy measurements which permit also to establish a–c and d–c conductivity contributions in this compound through Jonscher analysis. Furthermore, direct current I–V measurements revealed a Poole–Frenkel conduction mechanism at high temperatures with an activation energy of 1.55 eV. A comparison of these conduction processes was conducted to place this compound in the family of best materials for optoelectronic applications.

The regularities of impact heterovalent substitutions of atoms A- and B-positions on the slab perovskite-like structure of An+1BnO3n+1 type compounds were determined based on the analysis of structure Sr2-xLnxBIV1-xBIIIxO4 and Sr3-xLnxBIV2-xBIIIxO7 (Ln = La, Pr, Nd, Sm, BIII = In, Sc, BIV = Ti, Sn) types ompounds and phases. It was established that the inclusion of REE and indium atoms in the single- and double-slab structures of compounds Srn+1BIVnO3n+1 leads to increase the degree of interblockpolyhedra AO9 and octahedra BO6 deformation and a decrease the distance between adjacent perovskite-like blocks. Increase the degree of deformation of AO9interblockpolyhedra leads to increase in the tension in the interblock slab of Sr2-xLnxBIV1-xInxO4 and Sr3-xLnxBIV2-xInxO7 slab perovskite-like structure and the reduction of the distance between the two-dimensional perovskite-like blocks brings the structure of their two-dimensional slab perovskite-like structure closer to the structure of thermodynamically much more stable three-dimensional structures. The simultaneous combined action of these factors gradually destabilizes the slab perovskite-like structure and limits the region of its existence in the Sr2-xLnxBIV1-xInxO4 and Sr3-xLnxBIV2-xInxO7 series (in particular, it explains the absence of SrNdInO4 and SrLn2In2O7 (Ln = La – Sm) with slab perovskite-like structure). The significant influence of heterovalent substitution of atoms in slab perovskite-like structure of An+1BnO3n+1 type compounds on the structure of newly formed phases provides grounds for using this type of substitution for further targeted regulation of structure-sensitive properties of materials based on An+1BnO3n+1 type compounds with slab perovskite-like structure.

The demand for multifunctional materials with optical and electrical properties in industrial high-temperature applications has witnessed a rapid upsurge. Among ultra-high Curie temperature perovskite-like layered structure piezoelectrics, La2Ti2O7 (LTO) single crystal possesses the highest piezoelectric coefficient, but the lack of luminescence limits its optical applications. In this work, by combining experiments and first-principles calculations, we find that Sm3+ doped LTO single crystals not only create strong orange emission with high-color-purity and high-color-stability under high temperature/pressure, but also achieve higher piezoelectric coefficient of 21.7 pC/N at 298 K and 25.6 pC/N at 773 K, accompanied by polarization enhancement originating from inner TiO6 octahedral twisting. In addition, systematic high-temperature in situ electrical measurements showed that Sm3+ doping also contributes to weakening the adverse effects of ferroelectric–ferroelectric phase transition on piezoelectricity, dielectricity, and conductivity. Our work provides insights into the performance optimization mechanisms of ultra-high Curie temperature piezoelectrics and paves the way for the development of high-performance electro-optic integrated and coupled devices for applications under extreme conditions.

The desire to use novel functional materials in electrochemical devices stimulates significant research in materials science. Сomplex oxides with a perovskite-like structure occupy a large niche among such materials. Solid solutions based on LaInO3 exhibit promising ionic conductor properties (O2–, H+) combined with high chemical stability. This review presents a comprehensive analysis of the physicochemical properties of doped LaInO3 materials. The structure and hydration processes of parent and doped compounds are discussed. The transport properties data were collected and summarized. Both the pure and the doped materials exhibit mixed ion-hole conductivity in dry air. All solid solutions based on LaInO3 are capable of reversible incorporation of water vapor due to their effective oxygen vacancy size close to ran~1.4 Å. Under elevated humidity conditions, proton transfer is observed in the samples. The data indicates a correlation between an increase in free cell volume and an increase in ionic conductivity. The results on chemical stability and TEC for the pure and doped materials are analyzed. The strategy for selecting dopant cations is shown. The presented data show the potential for applications of LaInO3-based materials in electrolyte membranes for solid oxide fuel cells, pumps and sensors.

Lanthanum strontium ferrite (La0.85-xSr0.15AgxFeO3-δ x = 0; LSFO) and its silver-doped derivative (La0.85-xSr0.15AgxFeO3-δ x = 0.05; LASFO) are synthesized using mild conditions by a sol-gel method. Both oxides present a perovskite-like structure with orthorhombic symmetry due to octahedral tilting; thus, the incorporation of silver in the A-site does not significantly modify the perovskite structure. Exsolution of silver nanoparticles (AgNPs) from LASFO is induced under mild conditions, resulting in Ag@LSFO samples. X-ray absorption spectroscopy and synchrotron X-ray diffraction data reveal that the mechanism of exsolution involves the reduction of Ag+ and the concomitant release of oxygen, without altering the oxidation state of Fe, inducing the formation of oxygen vacancies in the perovskite matrix. Homogeneous distribution of AgNPs on the perovskite matrix is observed by high-resolution transmission electron microscopy. The thermal evolution of Ag@LSFO proceeds through the progressive increase in oxygen vacancies that become thermally disordered. The study clarifies the mechanism of silver exsolution and the structural changes in lanthanum-strontium ferrite perovskites, providing insights into their potential use in catalytic and energy-related applications.

The formamidinium copper formate [(NH2)2CH]Cu(HCOO)3 (FMD-Cu) with a perovskite-like structure based on a nonporous metal-organic framework (MOF), is presented for its synthesis and magnetic properties. The magnetic properties and their couplings to the structure are derived from detailed magnetic susceptibility and heat capacity measurements. We also discuss the spin exchange couplings based on density functional theory (DFT) calculations. As a result, FMD-Cu exhibits the unusual quasi-one-dimensional antiferromagnetic (AFM) characteristics with the Néel temperature TN = 12.0 K and an intrachain coupling constant J/kB ≈ 76.3 K. We also estimate the effective interchain coupling J*/kB≈ 4.24 K, suggesting that FMD-Cu is close to an ideal candidate for one-dimensional magnet. Furthermore, the heat capacity shows a transition to an antiferromagnetic ordering state appears around TN. Besides, the nonzero parameter γ = 0.089 J/mol K obtained from the linear relationship, γT, to the low temperature-dependent zero-field heat capacity data, can be associated with the magnetic excitations in insulating quasi-one-dimensional AFM Heisenberg spin-1/2 chains. The experimental estimate and DFT calculations are entirely consistent with a model of FMD-Cu in which AFM exchange interactions originating from Jahn-Teller distortion of the Cu2+ (3d9) ions, leaving a sublattice of coupled ferromagnetic (FM) chains. Hence, FMD-Cu is proposed as a canonical model of a quasi-one-dimensional Heisenberg spin-1/2 antiferromagnetic material.&#xD.

Understanding how doping influences physicochemical properties of ABO3 perovskite oxides is critical for tailoring their functionalities. In this study, SrFe0.67Cr0.33O3-δ epitaxial thin films were used to examine the effects of Fe and Cr competition on structure and B-site cation oxidation states. The films exhibit a perovskite-like structure near the film/substrate interface, while a brownmillerite-like structure with horizontal oxygen vacancy channels predominates near the surface. Electron energy loss spectroscopy shows Fe remains Fe3+, while Cr varies from ∼Cr3+ (tetrahedral layers) to ∼Cr4+ (octahedral layers) within brownmillerite phases and becomes ∼Cr4.5+ in perovskite-like phases. Theoretical simulations indicate that Cr-O bond arrangements and the way oxygen vacancies interact with Cr and Fe drive Cr charge disproportionation. High-valent Cr cations introduce additional densities of states near the Fermi level, reducing the optical bandgap from ∼2.0 eV (SrFeO2.5) to ∼1.7 eV (SrFe0.67Cr0.33O3-δ). These findings offer insights into B-site cation doping in the perovskite oxide framework.

Study of the physical properties of BiFeO3 films obtained by RF sputtering using a homemade target

Near-infrared (NIR) persistent luminescence (PersL) materials have unique optical properties with promising applications in bioimaging and anticounterfeiting. However, their development is currently hindered by poor red-light-exciting ability. In this study, CaTiO3:Cr0.001,Y0.02 (CTCY) was synthesized with 650 nm-excited 772 nm NIR PersL. The Y3+ doping in the Ca2+ lattice plays a key role in the PersL property. A charge compensation mechanism was proposed, in which Cr3+ in the Ti4+ lattice was stabilized by Y3+-doping while oxygen vacancies were generated to store the excitation energy at the same time. A thermal ionization mechanism might elucidate the red-light-excited NIR PersL of CTCY, which benefits from the perovskite structure of CaTiO3. CTCY has 120 times more intense red-light-excited PersL than Zn3Ga2Ge2O10:Cr. Its potential applications in luminescence anticounterfeiting and bioimaging were demonstrated using a visible/NIR dual-channel PersL flower painting and a CTCY-labeled bone screw for in situ reactivable PersL imaging using red light illumination instead of X-ray, respectively. This study not only provides a new NIR PersL material but also will add to our understanding in developing other potential red-light- or even NIR-activable PersL materials with perovskite-like structures.

Novel proton-conducting hexagonal perovskites Ba7In6–xYxAl2O19 for solid oxide fuel cells

Rare-earth titanate pyrochlores have attracted significant attention for their unique magnetic frustration; however, research on the origin of low-temperature dielectric dispersion and the relationship between dielectric properties and structure lags far behind. Here, by systematically investigating the dielectric properties of representative rare-earth titanates R2Ti2O7 (R = La, Nd, Sm, Er, Yb, and Lu), we demonstrate that R2Ti2O7 with a cubic pyrochlore structure exhibits low-temperature dielectric dispersion behavior, while the other compounds with a monoclinic perovskite-like layered structure possess no dispersion behavior but excellent temperature-stable dielectric property. The dielectric dispersion in cubic pyrochlores arises from the structural distortion. Furthermore, the existence of structural distortion is affirmed by the anomalous phonon softening of A1g Raman mode around the dielectric dispersion temperature, and the origin of the structural distortion is attributed to anharmonic phonon–phonon interactions induced by intrinsic vacant oxygen at Wyckoff 8a sites. In addition, with increasing ionic radius from R = Lu to Sm, the increased lattice parameter leads to varied bond length and bond angle of Ti-O(1)-Ti, which strengthens the local lattice distortion of TiO(1)6 octahedra and thus enhances diffusion degree of dielectric dispersion. On the other hand, the absence of intrinsic vacant oxygen site hardly gives rise to the local structural distortion and thus no dielectric dispersion in monoclinic R2Ti2O7. Our work not only clarifies the mechanism of dielectric dispersion but also gives a comprehensive perspective on the structure–property relationship of rare-earth titanates R2Ti2O7, and thus lays a solid foundation for further work on related materials.

As a typical Aurivillius-type compound, CaBi 4 Ti 4 O 15 (CBT) is considered a strong competitor among hightemperature piezoelectric materials, but it is difficult to achieve both high piezoelectric activity and a high Curie temperature for CBT. In this work, the method of double-ion co-substituting at different crystalline sites was used to modify the electrical properties of CBT. The Gd/Mn co-doped CBT ceramics with the chemical formula of Ca 1−x Gd x Bi 4 Ti 4 O 15 +0.2 wt% MnO 2 (CBT-100xGM, x = 0-0.11) were prepared via the conventional sintering process. The phase and valence band structures, chemical compositions and microstructures, dielectric and ferroelectric properties, electrical conduction behaviors, and electroelastic and piezoelectric properties of the ceramics were characterized. The doping concentration effects of Gd 3+ were analyzed according to the composition-dependent structures and properties of CBT-100xGM. The donor substitution of Gd 3+ for Ca 2+ at the A-site reduced the tolerance factor of the perovskite-like structure and decreased the concentration of intrinsic oxygen vacancies. While Mn 3+ tended to substitute for Ti 4+ at the B-site, the extrinsic oxygen vacancies are limited near the defect center of Ti(Mn) because of the formation of ( -Mn Ti ' ) • as defect dipoles. The thermal depoling behavior of the CBT-100xGM ceramics between 300 and 700 °C was explained by the thermodynamic characteristics of the defect dipoles. The optimized composition with x = 0.08 (CBT-8GM) had a high T C ≈ 809 °C and a high piezoelectric coefficient (d 33 ) ≈ 23 pC/N, as well as a piezoelectric voltage constant (g 33 ) value of up to 21.5×10 −3 (V•m)/N. Moreover, it can maintain a residual d 33 ≈ 80% after being annealed at 700 °C. This good anti-thermal depoling ability endows this material with great application potential in high-temperature piezoelectric devices with operating temperatures exceeding 500 °C. The synergistic enhancement in the piezoelectric activity and Curie temperature of CBT can be attributed mainly to the donorsubstituting effect of Gd 3+ at the A-site, as well as the decreased elastic compliance contributed by MnO 2 as the B-site dopant.