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Modification of bioceramics by ion implantation of magnesium (Mg) is of interest as Mg is the fourth abundant cation in the human body. In this work, magnesium was ion-implanted into a ZrO₂ based bioceramic stabilized with Y₂O₃ and Al₂O₃. Both Mg-implanted and unimplanted samples were soaked in a simulated body fluid (SBF) for a period of time. The deposits on the surface of various samples were characterized with scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). We find that the Mg-implanted ZrO₂ shows better bioactivity than the plain bioceramic. These results indicate that Mg-implantation can improve the bioactivity of the ZrO₂ based bioceramic. Mechanisms governing the improvement are discussed in this paper.

Nanocrystals of maghemite (γ-Fe₂O₃) have been prepared at the interface of organic-aqueous layer by the reaction of ferric acetylacetonate in toluene with sodium hydroxide in aqueous solution. The nanocrystals of γ-Fe₂O₃ formed at the interface of the organic-aqueous layer have been confirmed by X-ray diffraction (XRD) pattern. The sample has been characterized morphologically by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM) techniques. Magnetic hysteresis loop and zero-field cooling measurements exhibited superparamagnetism behavior for γ-Fe₂O₃ nanocrystals.

In the present work, the effect of K₂O/Na₂O substitution on the bioactivity of Na₂O-CaO-P₂O₅-SiO₂ ceramics prepared by solid-state method was studied. Ceramics-based bioactive implants are economical; they require low processing temperature and are more bioactive when compared with glasses, glass ceramics and composites. K₂O is known to control proper function of cells and stimulate bone formation process. The hydroxyapatite layer developed on the surface of samples after soaking in stimulated body fluid solution was studied by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and atomic absorption spectroscopy. The results showed an increase in the bioactivity of the samples as Na₂O was partially replaced with K₂O. The addition of K₂O enhanced the apatite-forming ability of the ceramic samples and makes it suitable for filling defects and fracture in bones.

Modern technology demands have raised the popularity of aluminum metal matrix composites (AMMCs) as it best suits diverse industrial applications. The need to develop an advanced functional material for specific applications attracts global researchers. Commercial needs for cost-effectiveness, quality improvement, superior performance and high strength to low weight ratio are met by composites. Mass production of AMMCs for specific industrial applications prefer stir casting as a simple and cost-effective manufacturing method. In addition, the production of composites turn more economic by reducing the weight percentage of ceramics and adding natural fibers either in the form of fibers, milled powder or ash to achieve the targeted properties. Process parameters being a dominating factor for minimal defect composites, their effect on final cast products are discussed along with strengthening mechanisms. This paper also discusses the applications, challenges and future scope of natural fiber reinforced AMMCs.

Ferromagnetic nanoparticles when dispersed in a dielectric ceramic matrix offer a new series of percolation composites with a metal-semiconductor or insulator interface that tailors the functional properties. In this purview, ZrO₂ of a high dielectric constant (ε_r) is stabilized in a cubic (c) polymorph by incorporating CrO₂ of strongly ferromagnetic nanoparticles. A selective composition 20CrO₂–80ZrO₂ is synthesized after heating a polymer precursor with glycerol at 500°C–800°C in air for 2 h. Broadening of X-ray diffraction peaks reveals Cr⁴⁺:c-ZrO₂ with an average crystallite size 5 nm in the 500°C heated sample and that is grown to 8 nm on increasing the temperature to 800°C. They occur as bundles of thin platelets in electron microscopic images. Both the samples have ferromagnetic hysteresis loops with 794 and 211 Oe of coercivities, respectively. Variations of ε_r-value and the power loss are studied as a function of frequency f (50 Hz–100 kHz range) on cold-pressed pellets at selective temperatures, in the 30°C–500°C range, in describing the effects of the magnetic species.

Properties of nanoscale materials are very interesting and these are either comparable to or superior to those of bulk. These materials are interesting due to their exciting size dependent optical, electronic, magnetic, thermal, mechanical and chemical properties. Different mole ratios of nanostructured mixed metal oxides of LaCo_xFe_1-xO_3-δ (x = 0 to 1) were prepared by the sol–gel method by varying the mole ratios of iron and cobalt substrates. The compounds were sintered for 700°C in the tubular furnace for 8 h. The purity of the compounds was analyzed by TG-DTA. The compounds were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM) studies were employed to study the structural phases, vibrational frequencies, surface morphology of the highest humidity sensing compounds.

With help of the method of the spark plasma sintering (SPS), the fine-grained (of micron approximately) ceramics based on various alumina nanopowders had created. A comparison of microhardness of ceramic samples obtained from 11 alumina nanopowders and 2 their composites was held. Microhardness of the ceramics obtained both by SPS, and by the traditional method (at successive pressing and sintering) is compared. The dependence of ceramics microhardness on the phase composition of the initial nanopowder and the average size of its particles was investigated. Besides alumina nanopowders (Al₂O₃), there were compared microhardness of ceramics from other 10 nanopowders of oxides (SiO₂, ZnO, Fe₃O₄, Gd₂O₃, CuO, WO₃, TiO₂, Y₂O₃, ZrO₂, MgO) obtained both by SPS, and by the traditional method. It is obtained that the microhardness of the ceramics created on the method of the spark plasma sintering, is significantly higher than a microhardness of the ceramics obtained by the traditional method; at the SPS method the average size of grain in ceramics decreases (to 1 micron and less).

La₂Zr₂O₇:Er, Yb nanoceramics have been obtained. Its structural and up-conversion luminescent properties were investigated. Under 980 nm laser excitation, the ceramics produced intense green and red up-conversion emission. The influence of Er³⁺ concentration and annealing conditions on the emission intensities has been discussed. The fabricated ceramics are expected to be an efficient up-conversion material with potential applications for laser diodes, display devices, detectors where the near infrared excitation is required.

The single-phase nanostructure forsterite powder was successfully synthesized by mechanical activation of talc and magnesium carbonate powder mixture followed by annealing in the presence and absence of ammonium chloride. Mechanical activation was used as an efficient method for the optimization of powder properties by means of combination and uttermost homogenization of the powder mass. Besides, the presence of chlorine ion affected the forsterite formation rate via producing smaller particle size during subsequent annealing which is very important in the case of diffusion-controlled reactions. The single-phase nanostructure forsterite powder with crystallite size of about 36 nm was successfully synthesized by 10 h mechanical activation with subsequent annealing at 1000°C for 1 h. While in the presence of chlorine ion, the single-phase nanostructure forsterite powder with crystallite size of about 20 nm could be obtained by 5 h of mechanical activation with subsequent annealing at 1000°C for 2 min.

Combustion synthesis has emerged as a facile and economically viable technique for the preparation of advanced ceramics, catalysts and nanomaterials. This paper is the report of the investigations carried out on the synthesis of titania–rare-earth mixed oxide pigments: TiCe_1-xPr_xO_4-δ by the solution combustion method and their characterization by X-ray powder diffraction, transmission electron microscopy, reflectance spectral data, thermal analysis and surface area measurements. The synthesized nanopigments exhibit yellow to brick red color with the increase of praseodymium content. The dominant reflectance of these pigments lies above a wavelength of 600 nm. These pigments are found to be promising candidates as ecological pigments because of their high reflectance, lightness and intense coloration.