Search

In this manuscript, the thin films of Magnesium Selenide (MgSe) were synthesized on a glass substrate using a single-stage horizontal tube furnace (SSHTF) which is supposed to be the simplest and a cost-effective approach. Before the deposition of thin films, the substrate was cleaned using standard methods. A pellet was formed by taking an equal ratio (1:1) of magnesium (Mg) and selenium (Se) powders and then evaporating them at 700oC for 1 h. The flow rate of nitrogen gas (100 SCCM) was maintained during the deposition process to avoid unwanted oxygen. A number of samples were synthesized by varying the source to substrate distance, and some representative samples are chosen for this study. The post-growth samples were characterized using XRD, SEM, and Raman Spectroscopy. The thermoelectric potential of all samples was tested by a home-developed Seebeck system. We have observed some promising values of the Seebeck coefficient (7.175 × 10−5 V/°C) and power factor (6.35 × 10−8 Wm−1oC−2) at optimized source-to substrate distance. These encouraging results will open the door for MgSe-based thermoelectric research and further explore its power generation potential in the future.

This paper reports the fabrication of (0 wt. %, 0.5 wt. %, 1 wt. %, 1.5 wt. %, and 2 wt. %) cadmium-doped tin sulphide (Cd-SnS) thin films using sol-gel technique via green synthesis route. Aloe vera gel is used as a green extract to fast fabricate Cd-SnS films. X-ray diffraction (XRD), UV-Vis spectrophotometer, four-point probe method, and J-V measurements are used to determine the crystallographic structure, optical, electrical, and photovoltaic properties, respectively. Here, the detailed structure properties like crystallite size, dislocation line density, d-spacing, and lattice constants of pure and Cd-SnS films are calculated. XRD confirmed the Cd doping in SnS with an orthorhombic structure. The film of 1.5% Cd-SnS showed good structural properties like large crystallite size (29 nm), small d-spacing (2.82 Å), small dislocation line density (1.18 × 1015 m−2), and lattice constants (a = 11.86 Å, b = 3.92 Å, c = 4.33 Å). Optical parameters like bandgap energy (Eg), extinction coefficient (k), refractive index (n), and dielectric constants (n) are calculated by using a UV-Vis spectrophotometer. Cd doped decreased the Eg of SnS. The low value of Eg (1.40 eV) is observed by 1.5% of Cd doping in SnS. A four-point probe approach is used to evaluate the sheet resistivity of Cd-SnS thin films at ambient temperature. The reduced value of sheet resistivity (1.3 × 104 Ω-cm) is achieved at 1.5% Cd doping. Solar cells of these films are fabricated. The geometry of the Cd-SnS solar cell is glass/FTO/TiO2/SnS/P3HT/Au. The open-circuit voltage (Voc), fill factor (FF), efficiency (η), and short circuit current density (Jsc) of solar cells are determined using a J-V curve. For pure SnS based solar cells, Voc is 0.702 V, Jsc is 2.04 mA cm−2, FF is 0.578, and η is 0.82%. All the factors except Voc are increased by Cd doping. The highest efficiency (1.34%) is obtained using a 1.5% Cd-doped SnS film-based solar cell. This efficiency is 61% higher than pure SnS based solar cells. These cells have a low-cost and long life time because there is no chemical corrosion like dye-sensitized solar cells.

Recently, the research on the remediation of aqueous organic pollutants over visible-light-active photocatalysts has got much attention. Therefore, this study reports the fabrication of visible-light-active Co3O4-Bi2O3 heterojunction photocatalyst for the photodegradation of rhodamine B dye. The Co3O4-Bi2O3 heterojunction was synthesized by the coprecipitation method and characterized by XRD, EDS, SEM, TEM, TGA, and FTIR. The as-prepared Co3O4-Bi2O3 heterojunction was utilized as a photocatalyst for the abatement of rhodamine B dye. It was observed that Co3O4-Bi2O3 showed the best catalytic performance with ∼92% degradation of rhodamine B dye than Co3O4 and Bi2O3 with 14 and 34% removal of rhodamine B dye, respectively. The rate constant for Co3O4-Bi2O3 catalyzed photodegradation of rhodamine B was 6 times and 3 times higher than the rate constant for Co3O4 catalyzed and Bi2O3 catalyzed photodegradation of rhodamine B, respectively. The as-prepared Co3O4-Bi2O3 exhibited the highest catalytic performance at pH 8.

The solid-state reaction method was selected to prepare polycrystalline AlFe1−xCrxO3 (x = 0, 0.02, 0.05, 0.07 and 0.1) samples. The Samples were found to be pure phases possessing the orthorhombic space group Pna21. The unit cell volume decreased with increases in the Cr content. The magnetic transition temperature and the saturation magnetization of the ceramics decreased due to dilution of the magnetic interaction with Cr content. The Dielectric responses were systematically investigated by temperature-dependent dielectric/impedance spectroscopy from 160 K to 500 K. It was noticed that incorporation of Cr3+ in the structure led to an increase in the dielectric constant up to x = 0.05 before decreasing, whereas the dielectric loss decreased. Two different dielectric relaxation processes that occurred in the grain interior of AlFe1-xCrxO3 polycrystals were clarified. One relaxation process was thought to be associated with localized transfer of electrons between Fe3+ and Fe2+, while the other arising at low temperature was assigned to interplay between lattice and polaronic defects such as oxygen vacancies.

Mossbauer spectroscopy, magnetic measurements, X-ray diffraction (XRD), as well as impedance analyzer are some of the techniques that have been employed in this study to evaluate how the dielectric, magnetic and structural properties of GaFeO3(GFO) ceramics are affected by Ti and Zn doping. polycrystalline Ga1-xZnxFe1-xTixO3 (0 ≤ × ≤ 0.1) were prepared by solid state reaction. They showed an orthorhombic crystal structure with Pc21n space group. The magnetic transition temperature decrease due to the dilution of the magnetic interaction. A noteworthy effect of substitution of multiple elements at the Ga and Fe sites on dielectric constant and tangent loss of GaFeO3 has been observed. Complete studies of temperature and frequency dependence of dielectric constant and impedance have provided the effect of grains and grain boundaries on the conduction mechanism and dielectric relaxation of the material. Impedance spectroscopy results have revealed a distinct conduction process at grain and grain boundaries. Keywords: Multiferroic material, Mossbauer analysis, Magnetism, Site disorder, Dielectric study

The polypyrrole (PPY/TW) and magnetic (MG/TW) composite with tea waste (TW) was prepared and used as an adsorbent for PO43− ions removal from aqueous media. The composite were characterized with SEM and FTIR techniques. Batch study was conducted to investigate the effect of different reaction parameters on the adsorption of PO43− ions. The native TW, PPY/TW, and MG/TW showed the PO43− ions removal of 7.2, 7.3, and 7.9 (mg/g), respectively, using 0.05 g adsorbent dose and 10 mg/L initial concentration of PO43− ions at pH of 6, 10, and 3, respectively, and equilibrium was reached in 90 min. Kinetics and isotherm models were employed on the PO43− ions adsorption data and PO43− ions adsorption followed the pseudo-second order kinetics, intraparticle diffusion, and Langmuir isotherm models. Thermodynamics analysis reveals an exothermic process and spontaneous adsorption of PO43− ions on the composites. Results revealed that the magnetic and polypyrrole composites with tea waste have auspicious potential as an adsorbent and this class of the composites can be utilized for the removal of PO43− ions from the effluents.

Polycrystalline samples AlFe0.95Cr0.05O3 synthetized by a solid state (SR) and a co-precipitation (cop) method show an orthorhombic system in space group Pc21n. It was found that, the cation distribution and magnetic ordering vary toughly on the synthesis conditions. We deployed impedance spectroscopy in studying the dielectric behavior of AlFe0.95Cr0.05O3. The significant results of this work are: for both samples, permittivity and dielectric loss are very sensitive to the temperature and frequency variation. The existence of supplementary imperfections and conducting species in AFCr5-s ceramics led to important dielectric permittivity in AFCr5-s. Values of the activation energy determined at low temperature point toward oxygen vacancies motion in slight range, however at high temperature, such a motion turns to long-range one. The dielectric response in case of AFCr5-s was assigned throw complex impedance plots to the grain as well as grain boundary. Conversely, additional individual pores similarly participate to dielectric belongings of AFCr5-cop.