Manganese vanadate microtubes have been synthesized by a facile polyvinyl pyrrolidone-assisted hydrothermal route. X-ray diffraction pattern confirms that the microtubes are composed of monoclinic MnV2O6, tetragonal V2O5 and orthorhombic MnO2 phases. The outer diameter and inner diameter of the microtubes are about 300 nm-3 µm and 200 nm-1 µm, respectively. The tube wall thickness of the microtubes is about 50 nm-1 µm. The possible formation process of the manganese vanadate microtubes has been proposed as a polyvinyl pyrrolidone-assisted growth mechanism.

Single crystalline Ca2Ge7O16 nanowires have been synthesized using CaO and GeO2 as the raw materials. Various factors that affect the formation and size of the Ca2Ge7O16 nanowires have been analyzed. The obtained products are characterized by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. The results show that the calcium germanate nanowires are composed of orthorhombic Ca2Ge7O16 phase with the length and diameter of several dozens of micrometers and about 50 nm, respectively. Hydrothermal temperature plays an important role on the formation and growth of the Ca2Ge7O16 nanowires. The formation process of the Ca2Ge7O16 nanowires is initially interpreted according to the shape evolution of the products obtained from different growth conditions.

Magnesium oxide and magnesium aluminate (MgAl2O4) spinel (MAS) powders have been synthesized by a simple aqueous sol-gel process using citrate polymeric precursors derived from magnesium chloride, aluminium nitrate and citrate. The thermal decomposition of the precursors and subsequent formation of cubic MgO and MAS were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry-differential scanning calorimetry (TG-DSC) and Fourier transform infrared spectra (FTIR). The single phase cubic MgO powder and MAS powder form after heat treatment at 800 and 1200 °C, respectively. The particle size of the MgO and MAS powders is about 100 nm and several micrometers, respectively. Ball milling eliminates the size of MgO and MgAl2O4 spinel powders by decreasing the conglomeration of the powders.