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Currently, developing materials with high power capability is crucial to the rapid deployment of electric vehicles. The Li4Ti5O12 (LTO) anode material with zero strain rate upon lithium insertion and extraction. The successful implementation of this anode material depends on strategies to overcome the low electronic and ionic conductivity. In this study, Li4Ti5O12 was synthesized using solid‐state approach in which different phases (anatase and rutile) of TiO2 as precursors were used. X‐ray photoelectron spectroscopy (XPS) and Raman analysis confirmed the formation of oxygen vacancies with the existence of Ti3+ ions, which is believed to greatly enhance the electronic conductivity of Li4Ti5O12. The electrochemical performance revealed that the rutile TiO2 precursor concentration significantly affects the resultant Li4Ti5O12 capacity and power capability. The Li4Ti5O12 synthesized using 80% anatase and 20% rutile TiO2 (N2‐LTO) exhibits a specific capacity of 169, 145, 140, 133, 122, 101, and 84 mAh g−1 at 1C, 3C, 5C, 7C, 10C, 20C, and 30C. In addition, LFP||N2‐LTO pouch‐cell was fabricated which showed promising results with 95% capacity retention after 1000 cycles at 1C rate. The oxygen vacancies created due to the presence of Ti3+/Ti4+ mixed valances and reduced particle size for faster lithium‐ion diffusion significantly enhanced the overall electrochemical performance. [ABSTRACT FROM AUTHOR]

Rare-earth element dysprosium (Dy)-doped SnO2 plays a crucial role in optoelectronics due to its tunable emission property in the visible region. Using simple spray pyrolysis process, trivalent rare-earth Dy (0–5 wt%) is successfully incorporated into the SnO2 lattice as Dy-doped SnO2 (DTO) thin films. X-ray diffraction measurements indicate that the films are considerably textured. Binding energy and elemental charge state are explored using X-ray photoelectron spectroscopy. Optical transmittance of 88.17% and band gap of 3.99 eV is observed for 2 wt% Dy-doped (DTO2) film. Among all the doped films, DTO2 film shows higher hydrophilicity (contact angle 70.7°) due to higher surface roughness (5.71 nm), which is beneficial for photocatalytic activity. The DTO2 film also shows highest carrier concentration (1.8 × 1019 cm−3) and electrical conductivity (3.19 Scm−1). Although, the electrical sheet resistance of the DTO films is high, it can be fine-tuned by further careful optimization of several deposition and/or doping parameters. It is observed that 2 wt% Dy doping into the SnO2 lattice aids the tunability of its optical and electrical properties according to device requirements. Photocatalytic activity of all the spray-pyrolyzed thin films is investigated by degrading methylene blue (MB) dye. The degradation efficiency is found to be highest for DTO2 film (~ 86% for 240 min) under visible LED light irradiation supported by a defect mediated mechanism. [ABSTRACT FROM AUTHOR]

Exploration of alternatives for supplementing indium tin oxide electrode is currently trending due to scarcity of indium, leading to a steep increase in the cost of related optoelectronic components. Codoping of niobium (Nb) and fluorine (F) into SnO2 lattice as cationic and anionic dopants, respectively, is explored by spray deposition technique. A fixed 10 wt% F and varying Nb concentration from 0 to 5 wt% is incorporated into the SnO2 lattice. X‐ray diffraction reveals substitution of Nb and F into the SnO2 lattice without altering the structure. Optical transmittance is found to increase with Nb content up to 4% of Nb (77.59%), and it decreases thereafter. Scanning electron microscope and optical profiler imply a relatively smooth surface with sharp‐tipped particles which vary with Nb concentration. Sheet resistance decreases up to 3 wt% of Nb doping and increases thereafter. Contact angle measurement indicates that upon doping with Nb, the films turn hydrophilic. Among the deposited films, 4 wt% of Nb‐doped film shows the highest figure of merit of 5.01 × 10−3 Ω−1. The surface work function of the 4 wt% Nb‐doped SnO2 film is 4,687.85 meV. The optimal films are tested as electrodes in dye‐sensitized solar cells and are discussed in detail. [ABSTRACT FROM AUTHOR]

Transparent conducting electrodes (TCEs) with high electrical conductivity and optical transmittance form an inevitable component in optoelectronic devices. Undoped SnO2 and Li (0 to 3 wt%): F (5 wt%) co-doped SnO2 films were deposited onto glass substrates using spray pyrolysis technique and are explored as alternative TCEs. Film crystallinity is found to improve upon co-doping with Li and F. Granular surface morphology is observed in the deposited films and least surface roughness of 25.1 nm is observed for Li (1 wt%): F (5 wt%) co-doped SnO2 thin film. The direct optical bandgap values of the films estimated using Tauc plot are in the range 3.02–3.21 eV. The Li (1 wt%): F (5 wt%) co-doped SnO2 thin film exhibits highest average optical transmittance around 90% at 550 nm. Photoluminescence emission measurements indicate the presence of oxygen vacancy defects which are estimated using Smakula's formula. The observed variation in sheet resistance is attributed to replacement of Sn atoms at the cationic sites in addition to the F atoms occupying the anionic sites, thereby creating deep donor levels. The high figure of merit value (378 × 10−6 Ω−1) indicates improved balance between transmittance and sheet resistance for Li (1 wt%): F (5 wt%) co-doped SnO2 film. The observed results advocate further exploration of the properties of Li:F co-doped SnO2 thin films toward potential alternative TCE system. [ABSTRACT FROM AUTHOR]

The viability of V2O5–Sn bilayer mesh film on ITO as an electrode system for inverted polymer solar cell (IPSC) is investigated. The metallic 'Sn' is expected to act as a plasmonic layer, enhancing the electron collecting ability of V2O5. X-ray diffraction peaks are indexed to ITO, Sn and V2O5. The direct bandgap of V2O5–Sn bilayer mesh film is estimated to be 2.80 eV. In the deposited V2O5–Sn mesh pattern, isolated globule morphology of 'Sn' is observed. The V2O5–Sn electrode shows improved values of carrier concentration (1.789 × 1019 cm−3) conductivity (1.218 × 102 S cm−1) and mobility (42.51 cm2V−1 s−1) compared to that of standard ITO electrode. Power conversion efficiency of 0.63% for the IPSC fabricated using V2O5–Sn electrode is three times higher than the efficiency using Ta:V2O5 electrode. This patterned electrode system has scope for further improvement by varying the mesh size and fine tuning Sn layer thickness below its skin depth. [ABSTRACT FROM AUTHOR]

Ternary perovskite oxides are potential candidates as stand-in electron transport materials to replace the conventional binary TiO2 in dye-sensitized solar cells (DSSCs). Here, we report the synthesis of nanostructured perovskite ternary oxide BaSnO3 (BSO) photo anode doped with lanthanum (LBSO) using a facile peroxide route and demonstrate the alternative efficient electron transport layers for DSSCs. A double surface treatment method with TiCl4 was initially applied to the transparent conducting layer (TCL) to enhance the performance of DSSCs based on La-doped BaSnO3. The DSSCs containing the pre-treated (TCL/LBSO3) exhibited better power conversion efficiency (PCE) of 4.37%. Furthermore, the DSSC device assembled with pre and post (TCL/LBSO3/TCL) surface treated film exhibited the highest PCE of 5.96%, which is 60% higher than DSSC with undoped, pre and post (TCL/BSO/TCL) surface treated film (3.71%). Hence, pre and post-treated LBSO3 can be considered a promising alternative ETL layer for DSSCs due to its superior charge collection efficiency and reduced recombination rates confirmed by impedance analysis. [ABSTRACT FROM AUTHOR]

Phase pure NdFeO3 has been achieved using high energy ball milling of oxide precursors with subsequent sintering. It is established that structural arrangement of NdFeO3 regulates the multifunctional feature of the material. Rietveld refinement of the room temperature X-ray diffraction pattern shows that the Fe-O-Fe bond angle significantly favors the super exchange interaction, which is predominantly antiferromagnetic in nature. Magnetization measurement illustrates antiferromagnetic behaviour with a weak ferromagnetic component caused by the canted nature of the Fe3+ spins at room temperature. Absorption bands in the visible ambit, apparent from the UV-Vis diffuse reflectance studies, is found due to the crystal ligand field of octahedral oxygen environment of Fe3+ ions. The direct band gap is estimated to be 2.39 eV from the diffuse reflectance spectrum. The lossy natured ferroelectric loop having a maximum polarization of 0.23 μC/cm² at room temperature is found to be driven by the non-collinear magnetic structure with reverse Dzyaloshinskii-Moriya effect. Magnetic field has influence on the dielectric constant as evident from the impedance spectroscopy, indicating the strong coupling between ferroelectric and the magnetic structure of NdFeO3. [ABSTRACT FROM AUTHOR]

Rare earth perovskite manganites have attracted renewed attention due to scientific aspect and prospective device applications. This work explores the structural and magnetic properties of La (1− x ) Bi x MnO 3 ( x =0–0.5) with isovalent Bi 3+ ions substituted at the La 3+ site synthesized through solid state reaction method. Doping of ‘Bi 3+ ’ in LaMnO 3 induces transition from orthorhombic to cubic phase for x ≥ 0.3. Decrease in the magnetic transition temperature in ZFC-FC data is correlated to the distortion induced by ‘Bi 3+ ’ doping. Spin glass like feature is witnessed in orthorhombic phase and it diminished appreciably for x ≥0.3 in the cubic symmetry. At 10 K, coercivity decreases in orthorhombic phase, whereas it increases marginally in cubic phase. Thus, isovalent Bi 3+ doping in LaMnO 3 is found to induce structural change from orthorhombic to cubic which is also reflected in the magnetic properties as a change over from hard to soft magnetic phase. In addition, a phenomenological model is applied for fitting the field cooled magnetization data. The results of fitting and the related magneto-caloric effect are also discussed in this paper. [ABSTRACT FROM AUTHOR]

Today is the era of Internet and networks applications. So the Information Security has been very important issue in data communication. Any loss to information can prove to be great loss to the organization. Encryption has come up as a solution, and plays a vital role in information security system. Many techniques are needed to protect the shared data. The present work focus on cryptography to secure the data while transmitting in the network. First the data which is to be transmitted from sender to receiver in the network must be encrypted using the encryption algorithms. Secondly, by using decryption techniques the receiver can view the original data. This paper provides a in depth comparison of five most common and used symmetric and asymmetric key algorithms: DES, 3DES, AES, RSA and MD5 algorithms and comparison has made based on their performance and time of encryption and decryption, block size, key size, and breakage of encryption/decryption time, throughput. [ABSTRACT FROM AUTHOR]

Highlights: [•] Undoped film was oriented along the 〈0 k 0〉 direction. [•] Mo 3d 5/2 and 3d 3/2 doublet caused by spin–orbit coupling are resolved with a splitting of 3.1eV. [•] Direct and indirect band gaps showed red shift with ‘Li’ doping compared to undoped film. [•] Intensity of the green photoluminescence emission spectra is quenched with ‘Li’ concentration. [•] Dye sensitized solar cell is fabricated using undoped MoO3 thin film as photoanode. [ABSTRACT FROM AUTHOR]

The electrical resistivity and magnetization of half-metallic/superconducting La0.7Sr0.3MnO3=Bi2Sr2CaCu2O8 (LSMO/Bi-2212) heterostructures are investigated with the thickness of Bi-2212 top layer fixed at 50 nm and that of the LSMO underlayer (t) being 40, 80 and 160 nm. Both the normal state resistivity ρ(290 K) and the superconducting transition width (δTC) increase with increasing t. On the other hand, the superconducting transition onset temperature (Tcon) of Bi-2212 monotonically decreases with increasing t, which is attributed to pair breaking via the polarized spins from the ferromagnetic LSMO due to strengthening of the magnetization. However, the rate of reduction of Tcon in Bi-2212 with respect to the thickness of LSMO is found to be much less in LSMO(t)/Bi-2212 compared with that of YBCO in the analogous system PCMO(t)/YBCO. From the qualitative analysis of the electrical and magnetic data we conclude that growing domains enhancing the magnetization is the reason for the thickness-dependent suppression of superconductivity in LSMO(t)/Bi-2212 bi-layers. [ABSTRACT FROM AUTHOR]

Abstract: The effect of Li (0–5wt%) doping on the properties of WO3 thin films deposited using an automated homemade spray pyrolysis unit is studied. Change in structural and optical properties is observed on doping with Li. The XRD patterns shows that undoped WO3 film has an orthorhombic phase while the Li (1–5wt%) doped WO3 films have tetragonal phase. The SEM and AFM images confirm relatively smooth surface of Li doped WO3 films compared to undoped WO3 film. Transmission spectra reveal that the transparency of the Li-doped films is much greater than that of undoped film. From the transmission data, the direct, indirect bandgap and phonon energies were calculated. Room temperature photoluminescence spectra showed pronounced blue emission on doping with Li. [Copyright &y& Elsevier]

Bulk Zn0.95TM0.05O (TM= Cr, Mn, Fe, Co, and Ni) were synthesized by the standard ceramic method and explored for variation in their band gap energies using Diffuse Reflectance Spectroscopy in the ultraviolet-visible region. Phase quantification and compositional studies were performed using Rietveld analysis of the X-Ray Diffraction patterns, Scanning Electron microscopy, and Energy Dispersive X-Ray Analysis. Due to 3d transition ion doping, the samples have brilliant colors, and the absorption edge of Zn0.95TM0.05O was found to shift towards the visible and ultraviolet-visible region. The blue and red shifts in band gaps observed for various transition metal ion-doped ZnO are discussed. [ABSTRACT FROM AUTHOR]

Abstract: Studies on spray deposited transparent conducting Li doped SnO2 thin films are scarce. Li (0 to 5 wt.%) doped SnO2 thin films spray deposited onto glass substrates at 773 K in air from chloride precursors were studied for their structural, optical and temperature dependent electrical behaviors. X-ray diffraction patterns indicated single phase with polycrystalline nature. Systematic variation in surface morphology on Li doping was examined by scanning electron microscopy and atomic force microscopy. Film thickness, optical band gap (direct and indirect), sheet resistance and figure of merit were computed from spectral transmittance and temperature dependent resistivity data. Lithium doping was found to decrease the value of sheet resistance by an order in magnitude. Activation energy was computed from temperature dependent electrical resistivity data measured in the range 300 to 448 K. The 4 wt.% Li doped SnO2 film was found to have a high value of figure of merit among other films. The results are discussed. [Copyright &y& Elsevier]

Abstract: ‘3d’ transition metal ion doped oxide semiconductors are widely studied for utilization in Spintronics. CuO, a p-type semiconductor with a band gap of 1.2eV was explored for ferromagnetic ordering by doping with Mn. Cu0.95Mn0.05O samples prepared by the standard ceramic and co-precipitation methods were analyzed using X-ray diffraction-Rietveld analysis, differential thermal analysis, scanning electron microscopy and energy dispersive X-ray analysis, respectively. Magnetic measurements using vibrating sample magnetometer on samples prepared by both the methods show possible ferromagnetic behavior at 77K. [Copyright &y& Elsevier]

Abstract: Nanoparticles of Zn1−x Fe x S with x =0.0, 0.1, 0.2, 0.4 and 0.6 were synthesized by chemical co-precipitation method, using thiophenol as the conditioning reagent. These nanoparticles were characterized by EDAX, XRD, TEM, optical absorption and magnetic studies. XRD studies revealed that the phase singularity of ZnS particles having zincblende (cubic) structure. TEM as well as XRD line broadening indicated that the average crystallite size in the samples was about 7nm. The optical absorption studies show a blue shift of the fundamental absorption edge with increasing Fe2+ doping. Magnetization measurements at room temperature revealed that all the doped samples were ferromagnetic in nature. [Copyright &y& Elsevier]

Abstract: ZnO substituted with transitional metal ions at the cationic site present interesting magnetic properties due to the strong sp–d exchange interaction which are expected to play a vital role in SPINTRONICS applications. The preparation route plays a vital role in the synthesis of single phase oxide diluted magnetic semiconductors (DMS). Zn0.95Ni0.05O prepared by both co-precipitation and ceramic methods were analyzed in detail by powder X-ray diffraction. Pelleted samples examined for their magnetic property using vibrating sample magnetometer indicated ferromagnetic-like behavior at 300K. Comparing the results of measurements performed on both the samples, we conclude co-precipitation method to be more effective in obtaining single phase compound with desirable properties by the relatively low temperature processing of the precipitated hydroxides. [Copyright &y& Elsevier]

Abstract: ZnO substituted with transitional metal ions at the cationic site presents interesting magnetic properties arising due to the strong sp–d exchange interaction. They are intensively explored for spintronics applications. The preparation route plays a vital role in the synthesis of single phase oxide Diluted Magnetic Semiconductor (DMS). Single phase Zn0.95Mn0.05O prepared by co-precipitation and standard ceramic methods was confirmed by powder X-ray diffraction measurements. The sample prepared by co-precipitation method was pelleted and examined for its magnetic property using Vibrating Sample Magnetometer (VSM) indicated ferromagnetic-like behavior at 300 K. Spin-glass state was observed at 77 K. Mn substitution in ZnO affects the transparency considerably in the visible region. Comparing the results of measurements performed on samples prepared by both the methods we conclude co-precipitation method to be more effective than ceramic method in obtaining single phase compound with desirable properties. [Copyright &y& Elsevier]

Abstract: Oxide-based ferromagnetic semiconductors are currently being explored for spin-based electronics (Spintronics) applications. Specimens of 1 and 2% Fe-doped Cu2O were prepared by varying the parameters of chemical co-precipitation technique. XRD analysis confirmed the cubic structure of Cu2O. Single-phase structure was obtained for the 1% Fe-doped Cu2O, whereas for the 2% Fe-doped Cu2O material, secondary phases were present (either CuO or Fe3O4). The morphology and composition were characterized by SEM and EDAX. Measurements made by vibrating sample magnetometry (VSM) indicated paramagnetic behavior at 300 K and diamagnetic behavior at 77 K for the 1% Fe-doped Cu2O. Diffuse reflectance (DRS) measurements indicated that a red shift in the band gap of Cu2O occurs on doping with Fe. [Copyright &y& Elsevier]