Investigation of Structures of Sintered Processed Fly Ash Materials: Resources of Industrial Wastes

The aim of the work is to use industrial waste as resource materials for formulating useful product for society. Materials are prepared using Fly ash as main ingredient through sintered process via solid state route. Different materials are prepared using various sintering temperature. The crystal structural and phases are explored by XRD analysis. Mulite phase are investigated, which is indicated the insulating properties of the materials. Surface topography of the prepared materials is analyzed by FESEM characterization. EDS analysis is also done during the FESEM characterization and is assessed the various chemical compositions. Identification of different chemical groups in the processed Fly Ash is carried out by FTIR analysis. Highest electrical resistivity is estimated and is found to be 35.1 MΩ, which indicates the very good insulating property.

Elaboration of a piezoelectric force sensor for medical application

In this work, a piezoelectric force sensor was fabricated based on Lead-Free ferroelectric particles (Na0.535K0.48)0.966 Li0.058 Nb0.9Ta0.1O3 (NKLNT) synthesized by solid-state route. A piezoelectric characterization by FTIR spectroscopy and dielectric characterization was performed. The manufactured NKLNT sensor shows excellent sensitivity and response to external mechanical forces, which implies that this sensor presents a promising technology for different applications.

Observation of Spin Reorientation Transitions in Lead and Titanium-Modified BiFeO3 Multiferroics

We report the synthesis and basic characterization details of bulk Bi1 − xPbxFe1 − xTixO3 (x = 0.05 and 0.1) polycrystalline samples, which have been synthesized using the conventional solid-state route. We studied the effects of partially doping of Pb and Ti ion on structural, vibrational, and magnetic properties of multiferroic BiFeO3. X-ray diffraction (XRD) was used for crystallographic studies, followed by Rietveld refinement, and phase formation of the compounds was confirmed, which indicates that the sample has rhombohedral (R3c, 100%) symmetry for x = 0.05 and R3c (98%) + P4mm (2%) symmetry for x = 0.1. X-ray absorption spectroscopy has been probed at Fe L2,3 and O K edges to determine the valence (charge) state of Fe in BiFeO3. Interestingly, the magnetic measurement results revealed the existence of spin reorientation transition in Pb and Ti-modified BiFeO3, which indicates that the BiFeO3 samples studied may find promising applications in memory and spintronic devices.

Crystal structure of mechanochemically prepared Ag2FeGeS4

Ag2FeGeS4 was synthesized as a phase-pure and highly crystalline product by mechanochemical milling from the binary sulfides and iron metal, followed by annealing in H2S atmosphere. The structure evaluation was carried out using X-ray powder diffraction with subsequent Rietveld refinements. As Fe and Ge atoms are not distinguishable using conventional X-ray methods, the chalcopyrite-type structure (space group I 4 ‾ 2 d $I‾{4}2d$ ), exhibiting a statistical distribution of Fe and Ge on Wyckoff position 4b, was considered. However, quantum-chemical calculations at hybrid density-functional level indicate that mechanochemically prepared Ag2FeGeS4 crystallizes in the kesterite-type structure (space group I 4 ‾ $I‾{4}$ ) where the cations are arranged in an ordered way. Ag2FeGeS4 is a further example of a mechanochemically prepared compound differing structurally from the commonly known polymorph exhibiting the stannite type (solid-state route).

Environmentally Benign Rare Earth Pigments: Effect of Calcium Dopant and Tuning of Bandgaps for Different Color Hues

Environmentally benign rare earth pigments having the general formula Ca0.1 Ln0.9 PO4 ( Ln = Y , Pr , mixed rare rearth oxides, RE and Di ) have been prepared by a traditional solid state route. The samples were characterized by X–ray diffraction diffraction, UV–vis Spectroscopy, scanning electron microscope (SEM), particle size distribution, color coordinates determination, acid/alkali test, thermo gravimetric (TG) analysis and CIE–1976 L*a*b* color scales. Among the various lanthanide ions and calcium ion as dopant, the pigment composition shows various hues ranges from green to yellow. The coloring mechanism is based on the tuning of band gap by the dopant like calcium in various rare earth host lattice. The designed pigments consist of non–toxic elements and were further found to possess high thermal and chemical stability. The pigments were also found to be appropriate candidates for the coloration of polymer substrates.Thus, the present environmental friendly pigment powders may find potential alternative to the classical toxic inorganic pigments for various applications.

Structural, magnetic, and gigahertz-range electromagnetic wave absorption properties of bulk Ni–Zn ferrite

Nickel–zinc ferrite (Ni0.5Zn0.5Fe2O4) powders were prepared by the conventional solid-state route and sintered at 1100 and 1300 °C for utilization as a tile electromagnetic wave absorber. Structural, magnetic, and microwave absorption properties were investigated by characterization techniques of X-ray diffraction, thermogravimetric analysis, Raman spectroscopy, electron microscopy, vibrating sample magnetometry, and vector network analyzer. The samples sintered at 1300 °C showed high magnetic saturation of 87 emu/g and low coercivity of 4 Oe. Electromagnetic investigations exhibit high reflection losses up to − 48.1 dB at certain high and low gigahertz frequencies, as clearly depicted in the 3D contour plot. The optimized condition between reflection loss, thickness, and bandwidth revealed a reflection loss of about − 36.1 dB at the matching thickness of 3.7 mm for the X-band. Furthermore, the effective working bandwidth at − 10 dB was up to ~ 7.1 GHz for the minimum thickness of 4.3 mm, which thoroughly covered the C-band. The microwave absorption performance of the well-sintered Ni–Zn ferrite was attributed to the incorporation of dielectric and magnetic loss mechanisms in which the magnetic part prevails.

Preparation and Thermogravimetric and Antimicrobial Investigation of Cd (II) and Sn (II) Adducts of Mercaptopyridine, Amino Triazole Derivatives, and Mercaptothiazoline Organic Ligand Moieties

The solid adducts of SnCl2.(3amt).H2O, SnCl2.2(3amt).H2O, CdCl2.(3amt), CdCl2.2(3amt), SnCl2.(2mct).0.5H2O, SnCl2.2(2mct), CdCl2.(2mct), CdCl2.2(2mct).H2O, SnCl2.(2mcp).1.5H2O, >2.2(2mcp).4H2O, CdCl2.(2mcp), CdCl2.2(2mcp), SnCl2.(4amt).4H2O, SnCl2.2(4amt).1.5H2O, CdCl2.(4amt).H2O, and CdCl2.2(4amt) (where the 3amt, 4amt, 2mct, and 2mcp represent 3-amino-1,2,4-triazole, 4-amino-1,2,4-triazole, 2-mercaptothiazoline, and 2-mercaptopyridine simple organic chelates, respectively) were prepared using a solid-state route and investigated by CHN elemental analysis and infrared spectroscopy. Additionally, we investigated the thermogravimetric characterization and antimicrobial proprieties. It is verified that for 3amt and 4amt adducts, the coordination occurs through nitrogen atom. For 2mct compounds, the coordination occurs through nitrogen (Sn) or sulfur (Cd). For 2mcp adducts, both coordination sites nitrogen and sulfur are involved. By examination of TG curves, it is confirmed that for each hydrated compounds, the first mass loss step is linked with the release of water molecules followed by the release of ligand molecules and sublimation of the metal chloride. Furthermore, it is verified that, considering only the release of ligand molecules (3amp, 4amp, 2mct, or 2mcp), the cadmium adducts are always more stable than the correspondent tin adducts probably due to the formation of cross-linking bonds in these compounds. Finally, of these 16 adducts, 14 showed antimicrobial activities against different bacterial and fungal strains.

Excellent piezoelectric property and thermal stability of Pb(Sc, Nb)O3-Pb(Hf, Ti)O3 ceramic

xPb(Sc 1/2 Nb 1/2 )O 3 -(1-x)Pb(Hf 1-y Ti y )O 3 piezoelectric ceramics were prepared by solid state route, and the phase structures and piezoelectric properties of ceramics were systematically investigated. Results showed that the sample with the composition of x=0.07 and y=0.53 possessed higher phase coexistence between the rhombohedral and tetragonal, and exhibited the optimal properties among different constituent systems, i.e. T C =355 °C, d 33 =400 pC/N, ε r =1390 and tan δ =1.05%. Furthermore, the effects of temperature on d 33 , leakage current density, P - E loop, and unipolar strain were studied for xPb(Sc 1/2 Nb 1/2 )O 3 -(1-x)Pb(Hf 0.47 Ti 0.53 )O 3 samples. The sample with x=0.07 revealed better temperature stability as well, the reason of which was analyzed in detail. The study indicates that the 0.07Pb(Sc 1/2 Nb 1/2 )O 3 -0.93Pb(Hf 0.47 Ti 0.53 )O 3 piezoelectric ceramic has excellently comprehensive properties suitable for application in higher temperature condition.