FeCo nanoparticles coated with (Fe,Co)3O4 (magnetite doped with cobalt) were synthesized by the proteic sol-gel chemical route. The synthesized materials were characterized by Thermogravimetry (TG), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), vibrating-sample magnetometer (VSM) and Mössbauer spectroscopy (MS). The results show that the increase in temperature and the choice of the correct air/N2 flow directly influence on the final physical-chemical properties of the nanocomposite. The SEM and TEM images confirmed that a thin layer of oxide was formed on the alloy, indicating that it was obtained a self-assembled FeCo-(Fe,Co)3O4 nanocomposites. In addition, the VSM results show that a possible exchange-spring coupling in magnetic FeCo-(Fe,Co)3O4 nanoparticles occurred with high saturation magnetization from FeCo alloy and high coercivity from (Fe,Co)3O4. The rotary oven allows the uniform contact of the powder with the atmosphere of synthesis during the different oxidation-reduction steps, generating more homogeneous particles.

Perovskite manganite La0.7Ba0.3MnO3, synthesized by ionic coordination reaction method (ICR) was compacted into pellets under different compaction pressures (Pc) and sintered at a temperature of 1150°C for 10h under a flow of O2. X-ray diffraction (XRD) data reveal that the samples can present simultaneously two phases - a rhombohedral structure with space group R3c and an orthorhombic structure with space group Pnma. Scanning electron microscopy (SEM) images show that, for this sintering temperature, the particle size and shape can be modified depending on the compaction pressure (Pc). Magnetization measurements show that the saturation magnetization and Curie temperature increase with Pc. The enhancement of the ferromagnetic properties of perovskite manganites La0.7Ba0.3MnO3 as a function of the compaction pressure is explained by an increase in the rhombohedral/orthorhombic structure ratio caused by this effect.

The ophthalmic dysfunction amblyopia, commonly known as lazy eye, is characterized by decreased vision in one eye due to improper development in childhood. The aim of this study was to obtain and characterize natural rubber membranes and to assess their utility as an eye film capable of altering the passage of light. The latex membranes were produced using the Van Gogh method and the deposition technique and were analyzed by physical and chemical methods to determine the properties of latex in natura and of natural rubber membranes. The materials were characterized by X-ray diffractometry, scanning electron microscopy, thermogravimetry, differential scanning calorimetry, analysis of water sorption and light crossing analysis. We report here a new approach to the treatment of patients with amblyopia using latex membranes.

Fe10Ag90 granular alloys have been prepared using a sol-gel process, sintered at 300 °C and annealed at temperatures between 400 °C and 700 °C. The mean size of the iron particles, obtained from X-ray diffraction, is 30.0 ± 0.7 nm. Due to the existence of a distribution of particle sizes in these samples, both blocked (BL) and superparamagnetic (SPM) particles are present simultaneously, as confirmed by magnetization measurements at room temperature. AC susceptibility measurements as a function of temperature reveal a magnetic phase transition at about 770 °C, indicating the presence of particles exhibiting bulk behavior, in the samples annealed above 550 °C. The presence of these particles has been attributed to an atomic diffusion process between the grains, forming bulk-like multiple-domain Fe particles having Curie temperatures near that of bulk alpha-Fe phase (T C = 770 °C).