Incorporation Of Sm Research Articles

Correlation of electronic structure and magnetic properties of [formula omitted] nanostructure using synchrotron soft XAS

The present study reports crystalline structure, electronic structure and magnetic properties for nanoparticles undoped CeO2 and Ce1-xSmxO2 (x = 0.02 to 0.10, @ 0.02). The nanoparticle samples are synthesized by the co-precipitation method. XRD data shows the successful incorporation of Sm3+ ions at Ce4+ sites in the face-centered cubic (fcc) lattice. The soft X-ray absorption spectroscopy technique is utilized to get an insightful overview of electronic structural properties due to structural defects, chemical states and the development of oxygen vacancies in Ce1-xSmxO2 nanoparticles. The soft XAS spectra show a significant Ce and Sm peak in the M4,5 domain, along with the well-defined O K-edge peak. Analysis of Ce M4,5-edges indicates that Ce-ions have both 3 + and 4 + oxidation states. With the incorporation of Sm+3 ions, there is a reduction of Ce4+ states and oxidation of Ce3+ states, as well as a substantial increase in oxygen vacancy concentration. The room-temperature magnetic properties of Ce1-xSmxO2 nanoparticles reveal ferromagnetic behavior. The origin of ferromagnetism is explained by F-center exchange (FCE) coupling mechanisms mediated via development of oxygen vacancy and defects.

Understanding of structural evolution, dielectric performance, and photoluminescence behavior of Sm-modified Na0.5Bi0.5TiO3

We present the crystal structures, dielectric and optical performance of Samarium doped NBT ceramic, (Bi(1−x)Smx)0.5Na0.5TiO3for x = 0.0, 0.01, 0.02, 0.03, 0.04, 0.05 fabricated by a solid-state reaction method. The Rietveld refinement outcomes of XRD data show that all the samples have rhombohedral crystal structures with the R3c space group. The variation of unit cell volume with composition displays an anomaly at x = 0.03. The Raman modes centered at 258 cm−1 and 535 cm−1 become broader with trivial smearing towards higher wavelength through a rise in Sm percentage. The temperature corresponding to maximum permittivity attains maximum value at x = 0.03. We found that dielectric loss decreases with increasing Sm content. The diffusing nature of the phase transition is enhanced with the rise in dopant concentration of Sm. The bandgap energy obtained from the reflectance data of UV–visible spectroscopy increases x = 0.03 and afterward simultaneously diminishes with Sm concentration. The photoluminescence study was carried out using the excitation spectra and emission spectra. The most intense emission has been observed at x = 0.03. Besides, a feeble green emission peak at 564 nm and two burly red emission peaks at 600 nm and 646 nm correspond to the 4G5/2→6H5/2 transition, and 4G5/2→6H7/2 and 4G5/2→6H9/2 transitions respectively. We expect that the incorporation of Sm in the NBT system will be a suitable method to highlight the multifunctional characteristics of the material for potential applications in devices having manifold functions incorporated with electrical and luminescence properties.

Intrinsic magnetic properties of (Nd1−xSmx)Fe11Ti

A series of (Nd1−xSmx)Fe11Ti alloys with the ThMn12 crystal structure have been fabricated and characterized in order to promote a strong uniaxial anisotropy in NdFe11Ti without the need of nitrogenation. The compounds show small changes in the lattice parameters and cell volume, as well as Curie temperature and spontaneous magnetization. The anisotropy field, however, rapidly increases with the incorporation of Sm and overcomes the effect of nitrogenation, reaching values>4 T for a 30% Sm content. Mössbauer spectroscopy indicates that the quadrupole splitting is correlated with the magnetic anisotropy. These alloys are good candidates for permanent magnets, provided the correct microstructure is developed to increase coercivity.

Redox-inactive samarium(III) acetylacetonate as dopant enabling cation substitution and interfacial passivation for efficient and stable CsPbI2Br perovskite solar cells

All-inorganic (CsPbX3) perovskites by replacing the volatile organic components with cesium cations allow extending the long-term thermal stability of perovskite solar cells (PeSCs) vs their organic–inorganic hybrid counterparts. However, the stability of α-CsPbI3 and α-CsPbI2Br still remains to be improved. In this work, we incorporate redox-inactive samarium acetylacetonate [Sm(acac)3] into CsPbI2Br to fabricate CsPbI2Br perovskite thin films. It is evidenced that Sm3+ not only partially substitute the Pb2+ sites to yield slightly contracted perovskite lattice but also modulate the perovskite growth and passivate the NiOx/CsPbI2Br interface. As a result, CsPbI2Br PeSCs based on stoichiometric and optimal Sm(acac)3 doping (0.15 mol. %) of CsPbI2Br show excellent photovoltaic metrics with a champion power conversion efficiency (PCE) of 12.86%. Moreover, the CsPbI2Br PeSCs exhibit enhanced thermal stability upon incorporation of Sm(acac)3, which retains 90% of their original PCE under heating at 85 °C for 200 h.

Auto-combustion synthesis and electrochemical studies of La0.6Sr0.4Co0.2Fe0.8O3-δ – Ce0.8Sm0.1Gd0.1O1.90 nanocomposite cathode for intermediate temperature solid oxide fuel cells

In the present study, a nanocomposite cathode comprising Fe rich La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) based pervoskite semiconductor oxide and Sm-Gd co-doped ceria rich Ce0.8Sm0.1Gd0.1O1.90 (CSGO) in the ratio of 1:1 has been successfully synthesized by a simple glycine nitrate auto combustion method. The structural properties of the two phase nanocomposite were evaluated by X-ray diffraction and Raman spectroscopy. A detailed electrical properties of co-doped LSCF-CSGO nanocomposites have been studied with a comparison of LSCF added with 10 mol% and 20 mol% Gd singly doped ceria (LSCF-GDC10 and LSCF-GDC20) nanocomposites as a function of temperature in the range of 673–1073 K at air atmosphere by AC impedance spectroscopy. The total electrical conductivity of the co-doped LSCF-CSGO nanocomposites has been found to be 0.043 S cm−1 at 973 K which is higher than that of the LSCF composite containing singly doped compositions. The Sm co-doping in GDC phase has effectively helped to reduce the undesired electronic conduction produced in the doped ceria as the electron concentration of LSCF-CSGO was found to be − 2.62 × 1015 cm−3 which was lower than the electron concentration of LSCF containing singly doped nanocomposite (LSCF-GDC20, − 2 ×1016 cm−3) estimated by Hall-Effect measurement. The activation energy of LSCF-CSGO nanocomposite has been found to be 0.05 eV for the oxygen reduction reaction by temperature dependent Arrhenius equation. The improved electrical properties in terms of high ionic conductivity and low activation energy have been achieved through the incorporation of Sm into GDC10 electrolyte phase in LSCF nanocomposite. The combustion synthesis method has also effectively helped to produce microstructure containing large grain size (~ 6 µm) which is beneficial for enlarging triple phase boundary (TPB) area of cathodes utilized in solid oxide fuel cells (SOFC) operated at reduced/intermediate temperature (673–973 K).

Effect of samarium (Sm3+) doping on structural, optical properties and photocatalytic activity of titanium dioxide nanoparticles

ABSTRACTThe current work reports the hydrothermal preparation of pure TiO2 and Sm3+ ion-doped TiO2 nanoparticles and the influence of samarium ion doping in the TiO2 host lattice. The as-synthesized both pure and Sm3+-doped TiO2 nano samples were extensively characterized by powder X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), energy dispersive X-ray spectroscopy (EDX) and UV–VIS spectroscopy. XRD pattern reveals the crystalline size and phase of the nanoparticles and the formation of spherical morphology was confirmed by HR-TEM observation. The incorporation of Sm in TiO2 is confirmed by EDX. The optical properties of TiO2 and Sm3+:TiO2 nanoparticles have been studied using diffuse reflectance spectroscopy analysis. The addition of the dopant ion markedly increases the bandgap from 3.39 to 3.46 eV. The photocatalytic activity of the crystalline as-synthesized nanoparticles was examined for the degradation of Rhodamine B induced by UV irradiation and the degradation efficiency is also reported.

Structural, optical, photocurrent and solar driven photocatalytic properties of vertically aligned samarium doped ZnO nanorod arrays

Vertically aligned, Samarium (Sm) doped zinc oxide (ZnO) nanorod (NR) arrays have been synthesized by simple vapour transport process. The samples were characterized by FESEM, XRD, PL, Raman spectroscopy and XPS. FESEM results showed that incorporation of Sm caused decrease in length of NRs from 25μm to 9μm and influence the alignment of NRs. The photocatalytic activities of methylene blue (MB) under natural sunlight irradiation results showed that the enhancement of photocatalytic efficiency from 83.02 to 97.3% for Sm doped (0–6%) ZnO NRs arrays and decreased 95.72% for higher concentration 8% of Sm. The photocurrent measurement shows photosensitivity increased from 1.085, 1.093, 1.268, 3.270 and 1.486 for ZnO NR arrays and Sm doped (2–6%) ZnO NR arrays and decreased for 8% Sm doped ZnO NR arrays. This result revealed that doping of Sm could enhance the visible-light-driven PC properties of ZnO.

Influence of Freeze-Dried Shrimp Meat in Pasta Processing Qualities of Indian T. durum Wheat

The present study aims to understand the influence of freeze-dried shrimp (Penaeus monodon) meat (SM) at different levels (2.5, 5, and 10%; w/w) in pasta processing. The rheological characteristics studies of SM-wheat flour blends indicated that dough stability increased with the increased addition of SM in the blends, whereas farinograph water absorption and amylograph peak viscosity decreased. Cooking loss increased with increasing levels of SM in the pasta (7.3% in 10% SM pasta; 6.7% in control pasta). However, all pasta samples were in the acceptable range. Color analysis of the pasta sample indicated that the L values increased with increasing levels of pasta. The instrumental texture of cooked pasta indicated that 10% SM pasta was significantly (p < 0.05) firmer (1.84 N) than that of the control (1.35 N). Microstructure studies revealed that incorporation of SM in the pasta had a better protein network. Pasta with 5% SM had the highest mean score for all sensory attributes, with increased levels of essential nutrients, fatty acids such as eicosapentaenoic acid and docosahexaenoic acid, and amino acids such as lysine.

Development of high-performance cathodes for IT-SOFCs through beneficial interfacial reactions

We propose a new way to develop high-performance cathodes for IT-SOFCs by utilizing the interfacial reactions. SrCoO x was selected as the starting electrode material, which took a vacancy-ordered 2H BaNiO 3-type structure and showed negligible ionic conductivity and low electrical conductivity. Phase reactions between SrCoO x and Sm 0.2Ce 0.8O 1.9 happened at 900 °C or higher, resulting in the incorporation of Sm and Ce into its lattice structure. This promoted the phase transition to a cubic perovskite and led to substantial increase in the electrical conductivity and oxygen mobility of the electrode. By utilizing such phase reactions, the SrCoO x + Sm 0.2Ce 0.8O 1.9 composite was developed into a high performance electrode with a low area specific resistance of 0.08 Ω cm −2 at 650 °C. An anode-supported cell with such electrode delivered a peak power density of 795 mW cm −2 at 600 °C.

Streptomycin as a selective agent to facilitate recovery and isolation of introduced and indigenous Sphingomonas from environmental samples.

Sphingomonas is an organism of major interest for the degradation of organic contaminants in soils and other environments. A medium based on the aminoglycoside antibiotic streptomycin (Sm) was developed, which, together with the yellow pigmentation of Sphingomonas, facilitated the detection, recovery and quantification of culturable Sphingomonas from soils. All 29 previously described bacterial strains belonging to 17 different Sphingomonas species were able to grow on mineral media containing 200 microg ml(-1) streptomycin, showing that the capacity to resist high concentrations of Sm is a common characteristic within Sphingomonas. Incorporation of Sm into the mineral medium led to a significant reduction in the background microbial population and a concomitant 100 times more sensitive detection of Sphingomonas inoculated in non-sterile soil matrices. The Sm-containing medium was used to examine a variety of hydrocarbon-contaminated soils for the presence and biodiversity of Sphingomonas. Incorporation of Sm in the medium led to a significant increase in the number of yellow-pigmented colonies. Comparison of contaminated and non-contaminated soils derived from the same site revealed colonization by culturable yellow-pigmented Sm-resistant bacteria of the polluted location solely. Both yellow and non-yellow-pigmented colonies were purified from plates containing glucose and Sm, and BOX-polymerase chain reaction (PCR) was used to sort out clonally related strains. Representative strains from the major BOX-PCR clusters were identified using FAME and partial 16S rRNA gene sequencing. Forty-eight of 58 Sm-resistant isolates were identified as Sphingomonas sp. Streptomycin-resistant Sphingomonas isolates generated BOX-PCR diversity patterns that were site dependent and represented different species mainly belonging to Sphingomonas subgroups containing species formerly designated as Sphingopyxis and Sphingobium. The ability to degrade phenanthrene was only found in a minority of the Sphingomonas isolates, which all originated from soils containing high phenanthrene concentrations.

YAG laser-induced β-BaB 2O 4 crystalline dot formation in Sm 2O 3–BaO–B 2O 3 glasses

A continuous-wave (CW) YAG laser (power: 0.75–0.9 J/s, irradiation time: 15 s–15 min) with a wavelength of 1064 nm is irradiated to 11.1Sm 2O 3·44.4BaO·44.4B 2O 3 glass, and the formation of β-BaB 2O 4 (β-BBO) crystalline dots with a diameter of 30–150 μm is confirmed from micro-Raman spectra. β-BBO crystals with around 200 μm length grow towards the interior of the glass. The incorporation of Sm 3+ into β-BBO crystalline dots is suggested from micro-Raman and fluorescence spectra. The second harmonic generation is detected from the array (10×10=100 dots) of β-BBO crystalline dots, indicating that each crystalline dot formed by YAG laser irradiation is a nonlinear optical crystal. CW YAG laser irradiation to glass with Sm 3+ ions is a nice technique for a spatially controlled crystal growth.

Spin-state transition in La1−xSmxCoO3 perovskites

Structural and magnetic properties of La1−xSmxCoO3 with x=0, 0.02, 0.04, 0.06, 0.08, 0.12, 0.16, and 0.2 have been systematically studied. LaCoO3 exhibits a rhombohedral structure of R3̄C symmetry. The lattice parameters decrease progressively with the incorporation of Sm, and a second orthorhombic phase of Pbnm symmetry appears for x⩾0.12. The volume fraction of the orthorhombic phase is a sensitive function of the Sm content in the compounds, and increases from 16% for x=0.12 to 75% for x=0.2. Accordingly, the low-spin-to-high-spin transition of the trivalent Co ions, characterized by a steep rise of the magnetization, shifts to higher temperatures. A molecular field analysis indicates an increased energy gap, from 317 K for x=0 to 500 K for x=0.2, between the low-spin and the high-spin state, implying a stabilization of the low-spin trivalent Co ions by the presence of Sm. The enhanced compressive chemical pressure due to the introduction of Sm is suggested to be responsible for the present observations.