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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]

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]

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]