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Non-stoichiometric lead free polycrystalline Sr0.8Sn0.2Bi1.75Sm0.25Nb2O9 (SSBSN) ferroelectric ceramics were synthesized through conventional solid step route method by incorporating ball milling and microwave sintering method. X-ray diffraction along with the Rietveld refinement technique confirms the single-phase orthorhombic structure with A21 crystal symmetry. Additionally, the short-range ordering was confirmed by Raman spectroscopy. Doping induced crystallite size and strain were further calculated from the Williamson-Hall plot, which comes around 150 nm and 1.48 × 10–3 respectively. A plate like morphology with an average grain size of 0.41 μm was confirmed by scanning electron microscopy (SEM). A diffuse type ferroelectric to paraelectric phase transition was recorded at 395 °C, mostly arising due to structural heterogeneity at the inter-ferroelectric phase boundary. The temperature and frequency-dependent dielectric measurement of SSBSN ceramic reveal a Maxwell–Wagner relaxation, with prominent dielectric loss in a low frequency regime perhaps due to the generation of leakage current in the SSBSN system. Frequency dependent ac conductivity indicates the polaron assisted hopping mechanism in SSBSN, which further obeys Jonscher’s formulation. The intra and intergranular contributions to impedance in SSBSN ceramics were probed by the complex impedance spectroscopy (CIS) technique. A non-Debye type relaxation mechanism in SSBSN ceramics was indicated by the Cole–Cole plot, whereas the conduction mechanism and transport properties were briefly studied using modulus spectroscopy. [ABSTRACT FROM AUTHOR]

The online version of the original article can be found at https://doi.org/10.1007/s00339-024-07482-y.Applied Physics A (2024) 130:342https://doi.org/10.1007/s00339-024-07482-y.In this article, author corrections should have been incorporated.The original article has been corrected.Publisher's NoteSpringer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.By Anurag Pritam; Gourav Bhattacharya; Saurav Sain; Vaibhav Shrivastava and Susanta Sinha RoyReported by Author; Author; Author; Author; Author [Extracted from the article]

• The Uniform deformation model (UDM) has been used to study the effect of strain and crystallite size on peak broadening. • P-E hysteresis loop specify the presence of ferroelectric properties in GdSBN, with remnant polarization of 0.9 µC/cm2. • Complex Impedance spectroscopy reveals NTCR behavior of the material that is associated to the multiple relaxation processes. Lead-free polycrystalline SrBi 1.75 Gd 0.25 Nb 2 O 9 (GdSBN) ferroelectric ceramics were prepared through a conventional solid-state reaction route by incorporating novel microwave sintering (MS) technique which effectively reduces the two-step sintering process to single step sintering. A single-phase orthorhombic crystal structure (A2 1 am) without any sort of impurities or fluorite phase was revealed from X-ray diffraction. The doping-induced strain was further studied using the Williamson–Hall (W-H) method, which comes around 1.3x10-3. The cross-sectional SEM micrograph confirmed the Aurivillius structure of the composition with an average crystallite size of 1.2 µm. The frequency (20 Hz–1 MHz) and temperature (25 °C–550 °C) dependent dielectric study of microwave sintered GdSBN displays a relative permittivity of the order of 103 at high temperatures and obeys Maxwell-Wagner relaxation. Additionally, a low dielectric loss of around 30 was observed from the dielectric spectroscopy. Dielectric characteristics further follow the diffused ferroelectric to paraelectric phase transition at 395 °C, which indicates the presence of space charge polarization in the system. The room temperature P-E hysteresis loop specifies the presence of ferroelectric properties in GdSBN, with remnant polarization (2P r) of 0.04 µC/cm2. Impedance and modulus spectroscopy reveal the non-Debye type relaxation and negative temperature coefficient resistance (NTCR) behavior of the material that is associated with the multiple relaxation processes. Temperature-dependent AC conductivity indicates an Arrhenius-type electrical conductivity of the order 10-7 S/cm and perfectly obeys Jonscher's formulation. The obtained results indicate that GdSBN Aurivillius composition can be used as a potential candidate for high-temperature piezoelectric sensors. [ABSTRACT FROM AUTHOR]

SrBi 2 Nb2O 9 belongs to the class of Aurivillius layered ferroelectric oxide materials and this article offers a suitable method for understanding the structural and electrical properties of this class material for industrial application. With this aim we have synthesized LaFeO 3 (LFO) doped Sr 0.8 Sn 0.2 Bi 2 Nb 2 O 9 (SBN) novel ceramic by solid state route using ball milling in an ethanol medium for 20 h with 200 rpm, followed by single-step microwave sintering. For better phase formation, the obtained powders are compressed into cylindrical pellets and fired at 1000 °C for 5 h. The sample was critically analyzed using powder X-ray diffraction data confirming the distorted perovskite structure. The dielectric properties were studied in a frequency range of 10 Hz to 2 MHz at different temperatures revealing many exciting results. Further analyzing the impedance spectroscopy gives an idea about the contribution of different electrically dynamic regions in different conduction processes. • Synthesized lead-free ferroelectric LSBN composition using solid-state route method, which is very challenging to execute. • The Uniform deformation model (UDM) has been used to study the effect of strain and crystallite size on peak broadening. • Impedance spectroscopy reveals that the relaxation mechanism in LSBN composition is a thermally governed process. • Contribution of capacitive elements to the total impedance spectra has also been investigated by employing modulus spectroscopy. [ABSTRACT FROM AUTHOR]

Hume‐Rothery rules along with Vegard's law form the basis of systematic doping variation resulting into similar changes in unit cell parameters and volume. Many recent reports have highlighted positive–negative departure from Vegard's law in binary semiconducting systems and a few oxide alloys as well. The current work targets investigations on the missing response of bismuth molybdate on low tungsten doping onto molybdenum sites (Bi2Mo1−xWxO6). Bismuth molybdate and bismuth tungstate have been widely reported for lattice oxygen migration‐driven photocatalytic response and pressure‐sensitive Raman scattering. Octahedral tilting in low‐tungsten‐doped Bi2Mo0.94W0.06O6 carries an interesting lattice oxygen folding toward a–c plane. As a result, unit cell polarity increases drastically and becomes a source for intense Raman scattering phase that is normally observable at pressures around 8.3 GPa. An interesting departure from Vegard's law behavior at around 5–6% tungsten doping confirms nearly identical unit cell structure rather than mix unit cell‐based alloy formation. [ABSTRACT FROM AUTHOR]

Transparent conductive oxides such as indium tin oxide (ITO) substrates are commonly employed as prime materials for optoelectronic applications. Enhancement in functions of such devices often compels stable and robust modification of the ITO substrate to improve its interfacial charge transfer characteristics. Thereby, in this work, naphthyl modifier multilayer films are fabricated on ITO substrate using conventional electrochemical reduction of 1-naphthyl diazonium salts (NAPH-D) via altering its concentration ranging from 2 mM to 12 mM with a step size of 2. Surface coverage was significantly tuned by varying NAPH-D concentration, keeping other parameters such as the number of scans and scan rate constant. For lower concentrations (2 mM), the molecular thickness ∼6 nm was obtained, whereas higher concentrations (12 mM) produced around 15–18 nm thickness. Atomic force microscopy (AFM), cyclic voltammetry, and electrochemical impedance spectroscopy (EIS) in the presence of a ferrocene redox probe also supports the formation of well packed molecular film grown on the ITO surface. Further, the wettability property of the grafted naphthyl film was investigated at different surface coverages and correlated with charge transfer resistance (RCt) obtained from EIS studies. [ABSTRACT FROM AUTHOR]

Microwave synthesized strontium bismuth niobate Sr 1-x Sn x Bi 1.95 La 0.05 Nb 2 O 9 (SSBLN) materials are investigated for non-Debye conduction and photocatalytic response. Lone electron pair repulsions between doping tin (Sn2+) and layer bismuth (Bi3+) generate optimal lattice strain. Lattice oxygen, that is critical in photocatalytic applications, is observed to fold along a-c plane on introducing tin. SSBLN compositions possess higher porosity with reduced dimensions. Porosity derived capacitive boundaries promote polaronic hopping in SSBLN materials over diffused ionic conduction. The visible spectrum photocatalytic response is better after doping tin in SSBLN compositions. Mesoporous network and electron-hole pair generation play crucial role in augmented photocatalytic behaviour of SSBLN materials. Image 1 • Asymmetric charge density of tin (in +2 form) induces maximum lattice strain in a-b plane. • Tin doping increases porosity as arranges more grains in limited volume. • Polaronic hopping developed due to tin doping converts SSBLN composition into a kinetically slow. • Tin-doped SSBLN shows improved photocatalytic behaviour due to microwave induced porosity and electron-hole pair generation. [ABSTRACT FROM AUTHOR]

This study investigates the impacts of structure and composition on the optical and electronic properties of a series of pyridinium-based bismuth iodide complexes. Organic substrates with various functional groups, such as 4-aminopyridine (4-Ampy), 4-methylpyridine (4-Mepy), 4-dimethylaminopyridine (4-Dmapy), and 4-pyridinecarbonitrile (4-CNpy) with different electron-donating and electron-withdrawing groups at the para position of the pyridine ring were employed. Crystallographic analysis reveals various bismuth iodide structures, including 1D chains and discrete 0D motifs. The optical band gap of these materials, identified via diffuse reflectance spectroscopy (DRS) and verified with density functional theory (DFT) calculations, is influenced by the crystal packing and stabilising interactions. Through a comprehensive analysis, including Hirshfeld surface (HS) and void assessment, the study underscores the influence of noncovalent intermolecular interactions on crystal packing. Spectroscopic evaluations provide insights into electronic interactions, elucidating the role of electron donor and acceptor substituents within the lattice. Thermogravimetric differential thermal analysis (TG–DTA) indicates structural stability up to 250 °C. Linear sweep voltammetry (LSV) reveals significant conductivity in the range of 10–20 mS per pixel at 298.15 K. X-ray absorption spectroscopy (XAS) at the Bi L3 edge indicates a similar oxidation state and electronic environment across all samples, underscoring the role of bismuth centres surrounded by iodides. [ABSTRACT FROM AUTHOR]

Microwave synthesis was optimized for preparing novel monoclinic Tin-doped barium niobate ceramics (Ba 1-x Sn x Nb 2 O 6 ; x = 0.0, 0.01, 0.05, 0.1, 0.2, 0.3) BSN. The intensity of monoclinic phase formation was observed to decrease on increasing tin as dopant indicating decreased crystallinity. Strained crystalline phase was observed in undoped sample that became severe on doping tin. Monoclinic metal alloy Sn 2 O 3 formation was confirmed on increasing tin doping beyond 5%. Electronic configuration of tin (II) oxide supports the local site-wise monoclinic disorder in crystal structure due to sterically active lone pair. Such a disorder arranges increased number of degenerate energy states and reduce effective energy gap between conduction band minimum and valence band maximum. All BSN compositions were investigated for monoclinic phase stabilization, ultra-violet absorption, dielectric response, raman modes and type of carrier concentration along with hall resistivity. All measurements possessed inflexion corresponding to 5% tin doping indicating successful site substitution and estimated Sn 2 O 3 metal formation beyond this. The values of reducing optical energy band gap, transparency to visible spectrum, hall resistivity and dc conductivity indicated utility of these materials as a target for growing transparent conducting oxide (TCO) films for substituting well-known indium tin oxide (ITO). • Microwave processing tailor flow of melt phases in Ba 1-x Sn x Nb 2 O 6 compositions to construct rare monoclinic structure. • Tin (p -block charge distribution) occupies more space in unit cell driving distortions in an interesting manner. • The evidence of SnO disproportion into SnO 2 and Sn 2 O 3 is confirmed through rise in direct current (dc) for 1% doped BSN. • An increase in covalence with tin doping is the source of alternative n-type and p-type semiconducting character of BSN. • Unstable Sn 2 O 3 phase is observed to stabilize due to quick cooling while withdrawing microwave power from 350oC to 25oC. [ABSTRACT FROM AUTHOR]

Pulp and paper industry generates large wastewater volumes containing recalcitrant and toxic compounds in various forms. These compounds are highly toxic and standard primary/secondary treatments are unable to filter heavy metal contaminants besides organic species. An emerging demand of advance level treatment is the motivation of current work that explores possibility of using thick sand of deep aquifers as an adsorbent to remove inorganic and organic contaminants simultaneously from wastewater besides desalination. Popular ultrasonic cavitation is used to accelerate degradation of toxic organic effluent into less toxic open ring structures besides curing heavy metals to form new bonds during adsorption. Because of extreme local environment due to cavitation, heavy metals coagulate in silicon-aluminum atomic meshes and carbon nano tubes for less toxic new crystalline structure. Significant changes in physico-chemical investigations like pH, chemical oxygen demand and colour towards drinkable water standards indicate effective adsorption resulting into wastewater purification. [ABSTRACT FROM AUTHOR]