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article i nfo Hard soft ferrite nanocomposites One-pot synthesis Spring exchange coupling Magnetic measurements Microwave absorption In this paper, we report a simple but novel aqueous solution based 'one-pot' method for preparation of (Ni0.65Zn0.35Fe2O4)x-(BaFe12O19)1 � x nanocomposites consisting of hard ferrite-soft ferrite phases. Nanocom- posites, having same compositions, have also been prepared by employing a physical mixing method. X-ray dif- fraction analysis showed the presence of nanocrystalline Ni0.65Zn0.35Fe2O4 and BaFe12O19 phases in the composites, prepared by both methods. However, transmission electron microscopic and scanning electron mi- croscopic analysis revealed that, nanocomposites, prepared by one-pot method, possessed better homogeneous

In this paper, we report a simple aqueous solution based chemical method for preparation of Cu nanoparticle loaded mesoporous silica SBA-15 (Cu@SBA-15) catalysts. Synthesized catalysts were characterized by powder X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), Fourier transform infrared spectroscopy (FTIR), high resolution transmission electron microscope (HRTEM), N 2 adsorption–desorption surface area and pore size analyzer, and particle size analyzer. Catalytic activity of Cu nanoparticle loaded SBA-15 towards reduction of various dyes, such as 4-nitrophenol, Methyl Orange, Congo Red, Rhodamine B, Methylene Blue and mixture of dyes were investigated in the presence of excess NaBH 4 . Catalysis reactions were monitored by employing UV–vis spectroscopy. Catalysis reactions followed pseudo-first order rate equation. These catalysts exhibited excellent catalytic activity and convenient recycling. The high catalytic activity, cost effectiveness and simple preparation methodology make 12.5Cu@SBA-15 an attractive catalyst for decolorization of organic dyes.

Series of single-phase Ni1 − xZnxFe2O4 (x = 0.20, 0.35, 0.50 and 0.60) nanopowders with average particle size of ∼ 35 nm have been synthesized by using oxalate based precursor method. Precursor powders were synthesized by reacting aqueous solutions of metal nitrates and oxalic acid by using different total metal ions: oxalic acid molar ratios and then evaporating them to dryness. Pure, single-phase Ni–Zn ferrite nanopowder was formed by calcining the precursor with total metal ion: oxalic acid ratio of 1:0.125 at a temperature of 850 °C. The synthesized nanopowders were characterized by using X-ray diffraction, Thermo-gravimetric and Differential Scanning Calorimetric analysis, Transmission Electron Microscope and Scanning Electron Microscope. Room temperature DC resistivity of the nanopowders was measured with respect to temperature by the two-probe method and was of the order of ∼ 107 Ωcm. Room temperature saturation magnetization was measured by using Vibrating Sample Magnetometer and it varied between 34–49 emu/g depending on the composition. This aqueous solution based method provides a simple and cost-effective route to synthesize single phase, Ni–Zn ferrite nanopowders.

Two simple chemical methodologies have been described for the preparation of single-phase α-Fe 2 O 3 nano powder with particle size ∼ 20–30 nm. Precursor powders were synthesized by reacting aqueous solutions of ferric nitrate and PVA and sucrose (method 1) and EDTA (method 2) and then evaporating the resulting solutions to dryness. The precursors were subsequently calcined in air for 2.30 hr at different temperatures ranging from 250 to 450 °C. The synthesized powders were characterised using TG-DSC analysis, X-Ray Diffraction, BET surface area measurement, SEM and TEM. DC electrical resistivity of the synthesized materials was measured by the two-probe method. The synthetic routes described here provide simple but cost-effective methods to produce single phase, α-Fe 2 O 3 nanopowder at a comparatively low temperature.