This study analyses the impact of Strontium (Sr) doping on the structural and physical properties of Yttrium iron garnet Y3Fe5O12 (YIG). The polycrystalline Y3-xSrxFe5O12 (x = 0.00, 0.05, and 0.10) specimens were synthesised via the solid-state reaction technique. X-ray diffraction with Rietveld refinement indicated that the compound crystallises in the cubic phase with an Ia3d space group. The doping has caused an increase in lattice volume due to lattice expansion. The FTIR and Raman spectra supported the monophase composition and indicated a linear trend of lattice expansion upon doping. XPS spectrum investigation confirmed the existence of multivalent states of Fe, which convert equivalently into the Fe4+ state upon doping. The magnetic hysteresis revealed its soft ferrimagnetic characteristics. The augmentation of double-exchange interaction from hole doping has led to a substantial rise in saturation magnetisation, reaching a peak value of 27.05 emu/g at a concentration of x = 0.1, so rendering it a feasible choice for the magnetic cores of electromagnets. The ferroelectric hysteresis loop demonstrated the resistive characteristics of YIG, marked by a decrease in polarisation due to the suppression of Fe2+ states. The dielectric investigation revealed the relaxation characteristics of YIG. Divalent doping has also resulted in a decrease in both the dielectric constant and the loss factor. This study will introduce an effective technique for producing high-performance YIG ferrite that meets the requirements of miniaturisation and integration.

In this study, the impact of morphological variations was investigated with respect to the structural, electrical transport, and magnetoresistance properties of La0.67Ba0.33MnO3 manganites, comparing their behaviours at both bulk and nanoscale levels. The structural analysis through Rietveld refinement confirmed the rhombohedral phase crystallization in both samples in R-3c space group. The SEM analysis revealed the crystalline nature of the bulk sample, while the nano sample exhibited particle agglomeration. Additionally, TEM imaging revealed a mean particle size 53.75 nm in the nano sample. The investigation of the metal-insulator transition (TMI) in the nano sample suggests an increase in electron-electron scattering at grain boundaries with diminishing grain size, resulting in a shift of the TMI to approximately 200 K. Below 50 K, the resistivity data indicated a Kondo-like transport behaviour. At the same time, the ferromagnetic-metallic region includes resistivity contributions from grain/domain boundaries, as well as electron-electron and electron-phonon scattering interactions. The conductive behaviour at temperatures above TMI​ was elucidated through the small polaron hopping (SPH) mechanism and the variable range hopping (VRH) model. Both bulk and nano LBMO samples showed resistivity dominance by grain boundary effects and electron-electron scattering, with the highest MR values recorded as 47.14 and 41.93, respectively, showing a decrease as grain size reduces.

Semiconductors are important for improving green technology by efficiently converting, storing, and transmitting renewable energy into electrical energy. A study was conducted to investigate the optoelectronic, thermodynamic, thermoelectric, and mechanical stability properties of RhTiP Half Heusler semiconductors using the FP-LAPW method in the WIEN2k. The structural parameters and SOEC's were determined using the GGA. The result showed that RhTiP is a non-magnetic material with confirmed mechanical stability. The strong anisotropy in RhTiP was reported. RhTiP is found to be an indirect-bandgap semiconductor with Eg = 1.027 eV within TB-mBJ. The maximum Seebeck coefficient obtained for RhTiP at room temperature is 1380 mu V/K. The electronic figure of merit corresponds to unity at a chemical potential (mu) of 0.25 eV. Finally, the dependence of some thermodynamic parameters with temperature and pressure was estimated from QH Debye model. The study suggests that RhTiP shows promising applications in thermoelectric and optoelectronic fields.

In this study, lithium copper pyroborate (Li6CuB4O10) was synthesized using the conventional solid-state reaction method to explore its structural, optical, and photocatalytic properties. Rietveld refinement of X-ray diffraction (XRD) data confirms that the compound crystallizes in a triclinic structure with a P1 (1) space group. The crystallite sizes were determined to be 71 and 79 nm, based on the Debye–Scherrer and Hall-Williamson methods, respectively. Fourier-transform infrared (FTIR) spectroscopy revealed characteristic BO3 stretching and bending modes, while X-ray photoelectron spectroscopy (XPS) confirmed the presence of all constituent elements. The bandgap energy was measured to be 2.1 and 4.4 eV, making it suitable for both UV and visible light photocatalysis. The calculated Urbach energy of 200 meV suggests that the optical bandgap is influenced by defects such as oxygen vacancies and lattice irregularities. Under optimized conditions (10 mg/L catalyst in 100 mL of 10 ppm methylene blue aqueous solution), Li6CuB4O10 demonstrated a photocatalytic degradation efficiency of 56.7

In the present work, the synthesis of BaZrO3 nano-ceramics is explored through flash combustion utilizing glycine as a fuel. The resulting nanoparticles exhibit a cubic Pm (3) over barm space group and a spherical morphology with an average size of 45.31 nm. XRD and EDAX verify the integrity of the phase. FTIR and Raman spectroscopy is used to analyze the molecular bonds and their vibrations, while XPS reveals surface compositions and oxidation states. The electro-optical properties of BaZrO3 are explored through UV-Vis spectroscopy and electronic band structure analysis. The Tauc plot displays a pair of band gaps, with values of 3.08 eV and 3.84 eV, corresponding to indirect and direct characteristics. BaZrO3 demonstrates photocatalytic potential with a degradation efficiency of approximately 36.41% for rhodamine B under visible light. Electronic band structure analysis reveals an indirect band gap of 3.05 eV in BaZrO3. The Bader analysis emphasizes the pronounced covalent characteristics present in the Zr-O bond. Photoluminescence spectra exhibit electronic transitions with a peak observed at 420.57 nm (similar to 2.94 eV), suggesting activity within the violet light spectrum. The CIE chromaticity coordinates imply prospective uses in the manufacture of violet-blue LEDs. These findings underscore the tailored properties of BaZrO3 nano-ceramics, showcasing their versatility for various applications, notably in advanced optoelectronic devices.

This study investigates the Half-Heusler (HH) ferromagnetic compound, GeKX (X = Ca and Sr) half-metallic (HM) characteristics through first-principle calculations within the density functional theory (DFT) framework. Utilizing spin-polarized calculations and employing the full-potential linearized augmented plane-wave (FP-LAPW) method and confirm the stability of both compounds in the ferromagnetic MgAgAs-type crystal structure with spacegroup 216 F4 3m . The structural characteristics are explored by employing the generalized gradient approximation, PBE-GGA, and local spin density approximation LSDA, to treat the exchange and correlation energies. In this work computed lattice constants align well with reported results. Analysis of the electronic structure within the MgAgAs-type structure reveals the HM nature of these compounds, each possessing an integer magnetic moment of 1 μB. Various electronic properties such as electronic band structures, densities of states, Fermi surfaces, and the origin of ferromagnetism are discussed using TB-mBJ approach. The evaluation of elastic constants has verified the mechanical stability of these compounds. By computing elastic constants, the obtained values for the bulk modulus, Young’s modulus, shear modulus, and Poisson’s ratio. Employing ELATE software, for visually depicted the anisotropic elastic properties in three dimensions, including values of linear compressibility, shear modulus, Young’s modulus, and Poisson’s ratio, along with an analysis of anisotropic factors. Furthermore, we investigated the thermoelectric properties of GeKX (X = Ca and Sr) alloys using the BoltzTraP2 code and found that the value of the figure of merit ZT is almost unity for both compounds. The robust HM characteristics of these compounds make them interesting candidates for spintronic devices.

Ferrite compounds have gained scientific attention for their multifunctional attributes. This investigation explores the structural, optical, dielectric and conductivity properties of polycrystalline gamma-Fe2WO6 synthesized by the solid state route. The X-ray diffraction confirmed the orthorhombic structure and single-phase formation, while the electron microscopy showed uniform distribution of dense micrometer-sized grains in gamma-Fe2WO6. The FTIR spectroscopy analysis validated the presence of active stretching and bending modes, signifying oxygen anion vibration at both Fe and W sites. The simultaneous presence of Fe2+ and Fe3+ ions in the matrix, as confirmed by X-ray photoelectron spectroscopy (XPS), results in an augmented optical energy band gap and contributes to dielectric permittivity due to the charge carrier hopping mechanism between the trap sites. The compound manifests semiconductor attributes, evident in its indirect optical band gap measuring 1.7 eV. It is observed that the compound has effectively degraded the Methylene Blue (MB) under the visible light within 40 min with a degradation efficiency up to 63 %. The material's electrical conductivity, follows the Jonscher's power law, signifies its semiconductor nature and adheres to the Small Polaron tunneling model for charge conduction between neighboring sites. The impedance (Z ') curves exhibit dielectric relaxation (<= 10 kHz) with a similar activation energy to the dc conductivity study. The activation energy, determined from both the impedance and conductivity analyses, indicates a connection with the migration of oxygen vacancies within the material. Our observation reveals the presence of oxygen vacancies, which possibly act as in-gap electron traps, enhancing the correlated optical and ac conductivity properties, making it an appealing material for diverse multifunctional applications.

Evolution of the structural, morphological and magnetic properties of Zn1-xMgxFe2O4 1-x Mg x Fe 2 O 4 (X = 0.00, 0.10 and 0.20) nanoparticles are discussed in detail and relation between cation disorder and magnetic interactions are prospected. The synthesized samples sintered at 500 degrees C temperature under examination display cubic crystal structure possesses Fd-3m as space group. The average crystallite size and lattice parameter shows variation as revealed from scherrer equation with the addition of Mg dopant at zinc site. Rietveld refinement presented single phase formation. Raman spectroscopy was utilized to convey different Raman modes and their associated vibrations. Scanning electron microscopy was utilized to survey the morphological attributes. Magnetization studies reveal weak ferromagnetism at low temperature (5 K) due to cation disorder for all samples. Zero field cooled and field cooled curves from magnetization vs temperature reveal the blocking temperature and its dependence on cation disorder and particle size. These results provide information about the possible applications of zinc ferrite nanoparticles in magnetic sensors, nanomedicine, optoelectronics, and memory devices.

This study explores how various surfactants (CTAB, PVA, and SLS) affect the properties of SnO2 nanoparticles synthesized via co-precipitation. The impact of these surfactants on crystal structure, microstructure, and bandgap characteristics was analyzed using XRD, FE-SEM, FTIR, UV–Vis-NIR, and PL spectroscopy techniques. The phase purity was assessed using X-ray powder diffraction and Fourier-transform infrared spectroscopy (FTIR), confirming a tetragonal rutile crystal structure (P42/mnm (136) space group). The crystalline size was determined via Scherer and Williamson-Hall techniques. FTIR analysis identified Sn-O vibrational modes and other functional groups. Scanning electron microscopy (SEM) revealed spherical-shaped particles with a flake-like grain structure, matching the crystalline size distribution. UV–Vis absorption spectroscopy explored optical properties, determining absorbance and optical bandgap using Tauc's plot. Photoluminescence (PL) response was observed under 248 nm illumination, showing peaks (363.6–558.6 nm) attributed to near band edge emission and defect energy levels from Sn interstitials and oxygen vacancies. CIE parameters, including color coordinates (x, y), color-correlated temperature of SnO2 nanoparticles. This study provides valuable insights into the potential applications of pure and surfactant-assisted SnO2 nanoparticles in optoelectronics.

In this study, we successfully synthesized the multifunctional Tetragonal-Tungsten Bronze (TTB) compound, Ba 4 Bi 2 Fe 2 Nb 8 O 30 (BBFNO), using a planetary ball-milling approach. Our investigation comprehensively spanned structural, vibrational, ferroelectric, optical, and photoluminescence characteristics. Phase purity was rigorously confirmed through Rietveld-fitted X-ray powder diffraction and Fourier-transform infrared spectroscopy (FTIR), unveiling single-phase crystals within a tetragonal structure in the P4bm space group. Notably, electron density plots revealed concentrated charges on the heavier atoms. Moreover, employing the Williamson-Hall method, we established the average crystallite size as 171.53 nm. Vibrational aspects were explored through Raman spectroscopy, while a dedicated polarization study validated the presence of ferroelectric properties. UV–Vis spectroscopy allowed us to pinpoint an optical bandgap of 3.07 eV using Tauc's plot. Further analysis of photoluminescence exposed the role of oxygen vacancies in influencing energy band gap shifts towards the visible spectrum, thereby affecting electronic transitions. Importantly, the CIE (Commission Internationale de l’e´clairage) chromaticity coordinates of BBFNO fell within the bluish-violet range, suggesting potential applications in optical and display technologies. The remarkable multi-functionality of BBFNO underscores its substantial promise for diverse technological applications.

We have observed the fragmentation of ferromagnetic-phase with Al3+ substitution in polycrystalline La0.6Sr0.4Co1-xAlxO3 (0 = x = 0.15) perovskite compounds. The introduction of non-magnetic Al3+ ions at the Co3+ sites results in several segregated ferromagnetic domains that interact and demonstrate cluster-glass-like behavior. The structural information and phase purity is determined with X-ray diffraction and Rietveldrefinement. The compounds crystallize in the R-3c space group with some iso-structural distortions. The soft X-ray absorption spectroscopy (SXAS) of cobalt L-2,L-3-edges revealed the heterogeneous electronic phase with a majority of Co3+ ions. The spin-only contribution of Co3+ and Co4+ to the net-effective magnetic moment confirms the presence of High-spin Co3+ (S = 2) and Low-spin Co4+ (S = 1/2) ionic species. The magnetization parameters (theta(p), Tc, Tb, C, and mu(eff)) observed from the (FC-ZFC) dc-magnetization measurements were suppressed with increasing Al3+ concentration. Inhomogeneous magnetic-phase transition is observed due to segregation in the ferromagnetic phase. Hence, in the parent compound, the intrinsic-ferromagnetism weakens with Al3+ substitution. Therefore, the long-range ferromagnetic-ordering fragments into several interacting FM clusters are isolated by a coexisting non-ferromagnetic (Al3+ rich) sub-lattice. The frequency-dependent magnetic acsusceptibility measurements determine a re-entrant cluster-glass nature which is analyzed with the Mydosh parameter (sic), Critical-Slowing-down of spins, and Vogel-Fulcher-formulation.

In this study, complex BiMn 2 O 5 (BMO) nanoparticles, well known for their applications in photocatalysts, magnetoelectric sensors, actuators, non-volatile information storages, and electrochemical supercapacitors, were synthesized through novel ultrasonication assisted sol–gel synthesis route. The corresponding Rietveld refinement confirms the monophasic nature of composition in Pbam space-group symmetry with orthorhombic structure. The morphological study examines the average grain size determined to be approximately around ∼ 64.50 nm, whereas, EDAX gives the elemental analysis. The vibrational modes of Mn–O and presence of other functional groups have been explored. The coexistence of the multivalency in Mn 4+ and Mn 3+ valence states, which are associated with the chemical stoichiometry of the synthesized compound is confirmed. The optimization of energy band-gap was attributed to influence the disordered crystal lattice and oxygen vacancies. The interesting Photoluminescence response of BiMn 2 O 5 NPs in visible region indicates strong purple-blue emission under excitation wavelength λ ex ~ 370 nm and CIE parameters. BMO nanoparticles have been evaluated as a photocatalyst for the decomposition of Rhodamine B dye under visible light illumination because of their low bandgap. In contrast, the presence of smaller nanoparticles and uncompensated spins depict M-H plot shows no saturation at high magnetic field, which manifest non-ferromagnetic correlation. The thermomagnetic study in field-cooled/zero-field-cooled modes also indicates an antiferromagnetic Neel transition at around 41 K. The results obtained from measurements and associated properties of nanoparticles give an insight of BiMn 2 O 5 nanoparticles for possible applications.

This report comprehensively investigates the crystal structure, magnetism, and transport properties of tungsten (W6+) substituted polycrystalline Ca4Mn3-xWxO10 (x = 0, 0.05, 0.1) compounds. The compounds were synthesized using the solid-state method and found to exhibit a single-phase orthorhombic structure confirmed by the Rietveld refinement. The substitution of (W6+) induces a change in the Mn octahedron and enhances the unit cell volume. The morphology indicates the crystalline nature of all the samples. The FTIR spectroscopic study revealed the position of the IR bands, which is highly sensitive to the oxidation state of Mn-ions. The shift to higher wavenumbers indicates reduced oxidation from Mn4+ to Mn3+ species. The appearance of the Mn4+ oxidation state in (x = 0) and the emergence of Mn3+ on W6+ substitution for (x = 0.05, 0.1) compounds are explored. The electrical resistivity plots revealed that compounds are semiconducting. The magnitude of re-sistivity decreases with W6+ substitution. The reported compounds exhibit a significant negative magneto-resistance towards lower temperatures. The compounds also demonstrate short-range ferromagnetic (FM) behavior attributed to the charge compensation effect's double exchange interaction (DE) connecting Mn4+ and Mn3+. The negative value of thermoelectric power (S) suggests the presence of charge carriers such as electrons, and the value of S first increased and then decreased in doped samples. The conduction in the studied compound is attributed to small polaron hopping.

In this study, pure and transition metal doped (TM = Fe, Co, and Ni), cerium oxide nanoparticles have been synthesized by the co-precipitation techniques. Rietveld refined X-ray diffraction (XRD) patterns affirm the monophase nature with cubic symmetry having an Fm3m space group and crystalline size varies in the range of 9-14 nm calculated by Debye Sherer's formulation. The morphological study has been done by scanning electron microscope (SEM) technique anticipated that agglomerated grains symmetry with the typical grain size distri-bution varies from 45 to 52 nm. The effect of transition metal doping on bending/stretching vibrational modes has been effectively investigated by FTIR analysis. The strong absorbance edge was seen in the UV region and shifted in the red region with the doping of transition metal ions. The tauc's plot of UV-vis absorption uncovers the bandgap decreased from 2.87 eV to 2.42 eV on transition metal doping. The photoluminescence spectroscopy (PL) technique was used to investigate the presence of oxygen vacancies and intrinsic defects in the host CeO2 lattice when doped with transition metal ions. These imperfections induce the lattice disorder and shift in the energy bandgap from the UV to the visible region of the spectrum by affecting its electronic transitions. The CIE chromaticity coordinates of pure and transition metal doped compounds observed in the blue region might be applicable in display devices. In this manner, these materials can be fascinating for tuneable electrical and optical devices.

In this work, we employ full potential linearized augmented plane wave approach based on the density functional theory to calculate the structural, electronic, and elastic properties of FeCrAs Half-Heusler compound. For electron exchange, we have considered the most common Generalized Gradient Approximation (PBE-GGA and PBEsol-GGA), as exchange and correlation potential for investigating these properties. The half-metallic ferromagnetic behavior is confirmed by density of states and spin-polarized band structures analysis, which show that the FeCrAs has an indirect band-gap in the spin-down channel and a metallic behaviour in the spin-up channel. Furthermore, the elastic constants (C-ij) and the related elastic moduli confirm their stability in the cubic phase and demonstrate their brittle nature. The Debye's temperature along with compressional, Shear and average elastic wave velocities has also been calculated. Copyright (C) 2022 Elsevier Ltd. All rights reserved.

Semiconductor materials of applicable structural and optical architecture are required for mitigating ongoing environmental issues, due to their ability to achieve a wide range of spectrum of solar light in various useful applications. In this work, Iron tungstate (Fe2WO6) powder was prepared through an easy ball-milling method. The stoichiometric ratio of high purity Fe2O3 and WO3 were calcined at 700 ? for 12 h and finally sintered at 850 ? for 24 h. The structural characterization for phase purity was per-formed by X-ray powder diffraction (XRD), followed by Fourier-transform infrared spectroscopy (FT-IR) and photoluminescence (PL) spectroscopy to gather the information about crystal structure and luminescent properties of prepared Fe2WO6 sample. The average crystallite size was calculated using the Debye-Scherrer formula. The presence of functional groups and vibrational modes of Fe-O and W-O have been confirmed by exploring the Fourier transform infrared spectrum. The Photoluminescence response of Fe2WO6 was observed by illuminating the sample with kexc ti 500 nm revealed green emission in the visible region. CIE chromaticity coordinates were also estimated from the photoluminescence emission spectrum of Fe2WO6 sample. Copyright (C) 2022 Elsevier Ltd. All rights reserved.

We have examined the impact of the monovalent Hg doping in polycrystalline Nd 0.8 Sr 0.2 -x Hg x CoO 3 (0 ≤ x ≤ 0.15) cobaltite samples by investigating their structural, magnetic, thermal, and electrical properties. These samples crystallized into the Pbnm space group, affirmed by Rietveld refined of powder X-ray diffraction data. The consequent grain morphology and elemental compositions of samples were revealed via scanning electron microscopy and energy-dispersive X-ray spectroscopy, respectively. The magnetization does not saturate in the M-H plots even at very high magnetic fields, indicating non-FM correlations. By curie-wise fitting, calculated θ P is negative for all samples, showing antiferromagnetic interactions dominating as increasing Hg+ content. The temperature dependence of electrical resistivity addressed that all samples exhibit a semiconducting nature. At high-temperature regions, the resistivity behavior of these compounds was explained by variable range hopping and small polaron hopping models. Increasing the Hg doping, the obtained parameters such as hopping distance and activation energy increased, whereas the density of state N ( E f ) at the Fermi level decreased. All samples have a positive Seebeck coefficient ( S ), and the value of S increased as Hg doping increased. The observed carrier concentration density decreases as Hg doping increased due to the “e g ” electron localization.