The performance of thermo-insulation rendering mortars with alternations in ratios of powdered cordierite and talc was examined. The goal was to confirm that recycled kilnware cordierite can be reapplied in the mortar design without significant deterioration in performance in comparison with OPC mortar. Differential thermal analysis was employed for examining thermally induced reactions. The cavitation erosion, in testing sequences ranging from 30 to 120 minutes, was used to assess the compactness of the mortar structure. The physico-mechanical properties of experimental mortars were investigated. The morphologies of the mortar tablets upon cavitation were studied using a scanning electron microscope. It was established that cordierite and talc filler in amounts up to 20% enhance microstructural packing and mechanical strengths due to improved cementation and therefore contribute to cavitation erosion resistance. Higher amounts of talc cause structural degradation and mass loss during cavitation tests. Reducing manufacturing costs, energy consumption, and greenhouse gas emissions are the main objectives of the production of this waste-based construction composite, as the reuse of waste materials can help achieve a number of Sustainable Development Goals.

As the demand for environmentally sustainable materials rises, particularly in applications like luminescent solar concentrators (LSCs) for urban environments, this study investigates the potential of volcanic rock-derived nanostructures from Lichadonisia Island, Greece. These nanostructures are designed to absorb sunlight and convert it to longer wavelengths efficiently. By grinding volcanic rocks and inducing nanostructure formation, followed by enrichment with FeO, enhanced luminescent properties were achieved. Comprehensive characterization using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), and Energy Dispersive X-ray Spectroscopy (EDS) confirmed the crystalline nature of the volcanic rocks and the presence of FeO in an amorphous state. FTIR analysis revealed characteristic peaks of volcanic rocks and additional vibrations from FeO, as well as modifications of Si-O-Al vibrations. FESEM-EDS observations indicated plate-like nanoparticle structures with FeO nanoforms on modified surfaces. Luminescence properties, assessed via Photoluminescence Excitation-Emission (PLE-PL) spectroscopy, showed that while pure nanostructures exhibited luminescence at 470 nm, FeO-enriched nanostructures demonstrated enhanced intensity and an additional emission peak at approximately 425 nm. These findings suggest that volcanic rock-derived nanostructures, particularly when enriched with FeO, offer significant potential for use in eco-friendly LSCs.

Dual-phase high-entropy rare-earth zirconates (RE2Zr2O7) have become an important development direction of new thermal barrier coating materials due to their excellent properties. Currently, dual-phase high-entropy RE2Zr2O7 is mainly prepared by conventional solid-state sintering. In contrast, little research has been reported on the rapid sintering of dual-phase high-entropy RE2Zr2O7 using ultrafast high-temperature sintering (UHS). Therefore, in this work, a novel dual-phase high-entropy (La0.2Sm0.2Gd0.2Y0.2Yb0.2)2Zr2O7 (LSGYY) ceramic was designed and prepared by UHS at 1700?C for 5 min. Structural analysis showed that LSGYY consisted of both pyrochlore and defective fluorite structures, and the rare-earth cations were uniformly distributed without segregation. Compared with Gd2Zr2O7 and La2Zr2O7, LSGYY exhibited excellent mechanical and thermal properties, including higher hardness (11.73 ? 0.58 GPa), higher fracture toughness (1.55 ? 0.26 MPa?m1/2), glass-like thermal conductivity (1.37 - 1.45 W?m-1?K-1), and higher coefficient of thermal expansion (11.67 ? 10-6 K-1), suggesting that LSGYY is a promising candidate for application as a novel thermal barrier coating material.

This study investigates the synthesis, characterization, and optical properties of cobalt-doped ?-tricalcium phosphate (Co-?TCP) nanoparticles prepared via microwave refluxing and sintered at 1000?C for 2 hours. Incorporating Co2+ ions into the ?TCP structure significantly influences its microstructural and optical properties. X-ray diffraction analysis (XRD) reveals a contraction of the crystal lattice upon Co2+ doping, attributed to the substitution of larger Ca2+ ions (ionic radius 0.099 nm) with smaller Co2+ ions (ionic radius 0.074 nm). This reduces lattice parameters, cell volume, crystallinity, and smaller crystallite sizes. The degree of crystallinity decreases from 89.56% for pure ?-TCP to 57.81% for 3Co-?-TCP. Scanning electron microscopy (SEM) shows that Co2+ doping produces more homogeneous powder with enhanced interconnectivity while maintaining a spheroidal agglomerated structure. The average particle size decreases from approximately 300 nm for pure ?TCP to 246 nm for 3Co-?TCP. Fourier transform infrared spectroscopy confirms the successful integration of Co2+ ions into the ?TCP lattice, evidenced by peak broadening and intensity reduction. Notably, incorporating Co2+ ions induces a striking colour change from white to pink, with intensity proportional to cobalt concentration. UV-Vis spectroscopy reveals characteristic absorption peaks at 530 and 678 nm, associated with Co2+ electronic transitions. The unique optical properties of Co2+ ions doped in ?TCP open up new possibilities for its use in bioimaging and drug delivery systems

WO3 thin films were prepared by RF sputtering metallic tungsten onto glass substrates, followed by thermal oxidation through annealing in air. This technique is straightforward, cost-efficient, and time-effective, achieving high deposition rates of 16 nm/min on average at 200 W magnetron power for the highly homogeneous W-metallic films. SEM/EDX analysis showed that after annealing at 450?C in air, the RF sputtered 269 nm thick metallic W films with a round grain morphology (~30 nm) turned into 420 nm thick nearly stoichiometric transparent WO3 (tungsten (VI) oxide) film, with a dramatically changed morphology of aggregated crystal rods approximately 1 ?m long. XRD and Raman spectroscopy confirmed a biphasic crystal structure, with a dominant monoclinic phase and a minor tetragonal phase. XPS analysis revealed the characteristic W4f7/2 and W4f5/2 electron peaks associated with the W6+ oxidation state, with no evidence of W5+ species, indicating a stoichiometric nature of the WO3 films.

Cadmium ferrite nanoparticles (CdFe2O4 NPs) have been synthesized by impregnation method followed by heat treatment. Investigation the structural and morphogical properties of CdFe2O4 NPs was done using XRD, FTIR and TEM techniques. On the other hand, CdFe2O4 NPs' magnetic characteristics were investigated. The success of the preparation technique utilized to produce pure nanocrystalline pure CdFe2O4 with a size of 26 nm was validated by XRD findings. According to FTIR based functional groups, the resulting cadmium ferrite has random spinel structure., The morphological characteristics of the synthesized ferrite, as determined by TEM technique, highlight the production of spherical-like particles at the nanoscale. Additionally, the prepared ferrite displays low magnetization and coercivety with paramagnetic behavior. The current work provides new opportunities for the simple, cost-effective, and efficient synthesis of nanomaterials for usage in useful application such as gas sensing and photo catalysis.

The microstructure and dielectric properties of manganese-doped zinc titanate (MnxZn1-xTiO?) ceramics were systematically studied for varying manganese concentrations (x = 0.1, 0.3, and 0.5). X-ray diffraction analysis confirmed the formation of a single-phase ilmenite-type hexagonal structure, reflecting the structural evolution with dopant concentration. Dielectric measurements revealed that the dielectric constant increased significantly with both manganese doping and temperature, while it decreased with increasing frequency. Similarly, dielectric loss exhibited a temperature-dependent rise and frequency-dependent decline. Notably, the partial substitution of Zn?? by Mn?? ions led to enhanced dielectric behavior, with the dielectric constant increasing by up to ~80%. These improvements underscore the material?s potential for use in high-performance dielectric and electronic applications.

This study investigates the cavitation erosion resistance of pyrophyllite-based composites reinforced with 20 wt.% of cordierite, mullite and zirconium-silicate, sintered at 1200 ?C. The phase composition and microstructural features of the sintered samples were analyzed using XRD and scanning electron microscopy (SEM). Cavitation resistance was evaluated using the ultrasonic vibratory method with a stationary sample according to ASTM G32, by monitoring the mass loss and surface degradation as a function of exposure time. The results show that the addition of refractory phases with higher hardness significantly improves the cavitation resistance of pyrophyllite. Among the investigated compositions, the sample reinforced with cordierite (P+C) exhibited the lowest cavitation rate (0.145 mg/min) and minimal surface damage, attributed to its compact and homogeneous microstructure that suppresses microcrack initiation and propagation. The samples containing zirconium-silicate (P+Z) demonstrated moderate improvement, while mullite-reinforced samples (P+M) showed the least enhancement due to their elongated grain morphology facilitating brittle fracture. These findings indicate that cordierite is the most effective reinforcing phase for improving the cavitation durability of pyrophyllite-based ceramics, enabling their potential application in hydrodynamic systems exposed to cavitation-induced wear.

Ceramic Matrix Composites (CMCs) are transformational materials with outstanding thermal stability, mechanical strength, and resilience to severe conditions, making them important in aerospace, energy, and defence applications. This paper examines the novel approaches and problems of creating CMCs for ultra-high-temperature settings, emphasizing material selection, reinforcing strategies, and advanced production techniques. Recent improvements include using silicon carbide (SiC) and zirconium oxide (ZrO?) as matrix materials and reinforcements, such as continuous fibers and whiskers, to improve performance. Advanced processing methods, such as Polymer Infiltration Pyrolysis (PIP) and Chemical Vapor Infiltration (CVI), provide precise microstructure customization for high-demand applications. Despite these gains, challenges such as oxidation resistance, surface degradation, and cost-effective scaling persist. Integrating non-destructive evaluation techniques and adhering to high-quality standards is essential for boosting reliability. This review emphasizes the promise of CMCs in satisfying critical technological objectives while underlining the need for continuous research into processing advancements and environmental durability to enhance their application in ultra-high-temperature sectors.

In this study, carbon black (CB) obtained from the pyrolysis of waste tires was used as a reinforcement material. Al6061 alloy, widely utilized in the automotive industry, was selected as the matrix material, while silicon carbide (SiC) was employed as a secondary reinforcement. The study investigated not only the feasibility of using CB as a reinforcement material but also its compatibility with SiC. The mechanically mixed powders were compacted under a pressure of 450 MPa for 1 minute and sintered at 640?C for 360 minutes, producing the composites via the powder metallurgy (P/M) method. Microstructural images and EDS analyses revealed the presence of carbon black within the internal structure, a homogeneous distribution of the reinforcing elements, and the absence of agglomeration. Significant increases in hardness were observed with higher reinforcement content. The hybrid composite reinforced with 5% CB and 7% SiC exhibited a 101.28% increase in hardness compared to the Al6061 alloy. The most substantial reduction in wear rate, 252% relative to the Al6061 alloy, was identified in the composite reinforced with 10% CB. Furthermore, the thermal conductivity of the Al6061 alloy, initially 167 W?m???K??, decreased to 141.5 W?m???K?? with the addition of 7% CB. In conclusion, the addition of CB significantly improved the hardness and wear resistance of the composite while reducing its thermal conductivity.