Lattice variation as a function of concentration and grain size in MgO-NiO solid solution system.

The study aimed to understand how changes in crystal's size affect the lattice parameters and crystal structure of MgNiO solid solution for six X values ranging from x = 0 to x = 1. MgNiO was synthesized via two different wet-chemical techniques: the sol-gel and the microwave hydrothermal method, both followed by calcination at different temperatures of 673, 873, 1073, 1273 and 1473 K. As annealing caused grain growth, the varied temperature range allowed to examine a wide range of grain sizes.

Phase Stability of Nanocrystalline Grains of Rare-Earth Oxides (SmO and EuO) Confined in Magnesia (MgO) Matrix.

Rare-earth (RE) oxides are important in myriad fields, including metallurgy, catalysis, and ceramics. However, the phase diagram of RE oxides in the nanoscale might differ from the phase diagrams for bulk, thus attracting attention nowadays. We suggest that grain size in the nanoscale also determines the obtained crystallographic phase along with temperature and pressure.

The new nano-enabled phase map of ZrO-AlO.

Rapid development of nanotechnology often requires verification of existing phase diagrams, which were suitable for bulk materials. This work presents a new phase map (phase diagram) for AlO-ZrO crystalline powders including the role of the nanoscale particles. AlO-ZrO composites are relevant for industry for applications demanding high hardness.

Mechanism of Reduced Sintering Temperature of Al₂O₃⁻ZrO₂ Nanocomposites Obtained by Microwave Hydrothermal Synthesis.

A novel method to obtain Al₂O₃⁻ZrO₂ nanocomposites is presented. It consists of the co-precipitation step of boehmite (AlO(OH)) and ZrO₂, followed by microwave hydrothermal treatment at 270 °C and 60 MPa, and by calcination at 600 °C. Using this method, we obtained two nanocomposites: Al₂O₃⁻20 wt % ZrO₂ and Al₂O₃⁻40 wt % ZrO₂.

Internal Nano Voids in Yttria-Stabilised Zirconia (YSZ) Powder.

Porous yttria-stabilised zirconia ceramics have been gaining popularity throughout the years in various fields, such as energy, environment, medicine, etc. Although yttria-stabilised zirconia is a well-studied material, voided yttria-stabilised zirconia powder particles have not been demonstrated yet, and might play an important role in future technology developments. A sol-gel synthesis accompanied by a freeze-drying process is currently being proposed as a method of obtaining sponge-like nano morphology of embedded faceted voids inside yttria-stabilised zirconia particles.

Ultrasonic cavitation of molten gallium: formation of micro- and nano-spheres.

Pure gallium has a low melting point (29.8°C) and can be melted in warm water or organic liquids, thus forming two immiscible liquid phases. Irradiation of this system with ultrasonic energy causes cavitation and dispersion of the molten gallium as microscopic spheres.