Poly (vinylidene fluoride) (PVDF) composites with high loadings (50-65 wt%) of waste-derived fillers—alum sludge (AS), an inorganic water treatment residue, and wood dust (WD), a lignocellulosic timber by-product—were prepared via melt compounding and compression moulding without compatibilisers. Mechanical, thermal, and dielectric properties were systematically characterised. Increasing filler loading enhanced Young’s modulus but reduced elongation and impact resistance due to restricted chain mobility and stress concentration. Dielectric behaviour differed markedly between the two systems: AS composites exhibited progressive increases in relative permittivity (up to ~70%) attributed... More >

In this work, \((1-x)\text{Ba}_{0.85}\text{Ca}_{0.15}\text{Ti}_{0.9}\text{Zr}_{0.1}\text{O}_{3} - x\text{Sr}_{0.7}\text{Bi}_{0.2}\text{TiO}_{3}\) (BCZT–SBT) ceramics with \( x = 0 \) and \( x = 0.025 \) were prepared through the conventional solid-state route. The samples were calcined at \(1200\,^{\circ}\text{C}\) for \(6\,\text{h}\), then re-milled, pressed into pellets, and sintered at \(1325\,^{\circ}\text{C}\) for \(6\,\text{h}\). XRD patterns indicate the formation of a cubic perovskite structure. A small decrease in lattice parameter is observed upon introducing SBT (\(a\) decreases from \(4.0176\,\text{Å}\) to \(4.0149\,\text{Å}\)), accompanied by a slight reduction in unit-cell... More >

This study focuses on the solid-state processing optimization of SrTi\(_{1-x}\)Fe\(_x\)O\(_3\) (STFO) ceramics with \(0.00 \leq x \leq 0.11\). X-ray diffraction reveals a single-phase cubic structure (space group Pm\(\bar{3}m\)) with lattice constant \(a = b = c = 3.91{Å}\) and a maximum relative density of \(\sim\)94%. SEM confirms well-formed grains in both pure and Fe\(^{3+}\)-doped SrTiO\(_3\). TGA/DSC indicates low weight loss and high thermal stability for the \(x = 0.09\) composition. Electrical conductivity increases with frequency, accompanied by higher dielectric losses for \(x = 0.09\) and \(x = 0.11\). FTIR verifies the Ti-O octahedral stretching frequency at \SI{530}{\cm^{-1}},... More >

Halide double perovskites offer wide compositional flexibility and are being explored for energy-related applications. In this work, the structural, electronic, optical, and thermoelectric properties of Li\(_2\)AgSbX\(_6\) (X = F, Cl, Br, I) were investigated using density functional theory (DFT) within the WIEN2k package. Structural optimization shows a systematic increase in lattice parameter from F → I, accompanied by a decrease in bulk modulus, indicating higher compressibility for the heavier-halide compounds. Electronic-structure calculations within PBE-GGA identify all compositions as indirect-gap semiconductors, with band gaps decreasing across the series: 1.599 eV (F), 1.389 eV (C... More >