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We have obtained ceramic composites containing graphene structure, where homogenization process of powdery composite was improved. At first, α-alumina was obtained from local row, which is cheap and available. The obtaining method was developed by our group. Graphene oxide was synthesized from natural graphite. Homogenization was carried out in nanomill with organic binder, which provides for equal distribution and separation of graphene oxide layers (Organic binder behaves as “scotch tape”) during grinding. Some characteristics of ceramic materials have been improved.

Powder of magnesium diboride was obtained by solid phase reaction of mixture of magnesium (> 99% pure) and amorphous boron (> 99% pure) powders at 650-900 °C temperatures in inert atmosphere. During synthesis process main attention was paid to removing oxide layer of surfaces of powder particles by organic solvents in Glovebox, where concentration of oxygen and water steam is less than 5 ppm. Homogenization and activation of powders were conducted in a planetary nano-mill by WC balls in an inert area. Pressing of the obtained powders was conducted in an argon atmosphere. MgB 2 nonstoichiometric powders contained excess boron and magnesium. Magnesium hydride was used as source of excess boron, which is fragile compound and easy to grind in nano-mill. It decomposites with metallic magnesium and hydrogen up to 280 °C temperature. Commercial magnesium diboride powder (Aldrich, > 99%) was used for fabrication of MgB 2 bulk targets. Powders systems of MgB 2-Mg, MgB 2-MgH 2 , MgB 2-B homogenized by nano-mill in Glove box was used for fabrication of composites with nonstoichiometric contents. The targets were cylinders with diameters of 27-52 mm and height of 5-15 mm. Consolidation of pressed powdery composites was conducted in argon atmosphere. Synthesis of MgB 2 from mixture of magnesium and amorphous boron powders and simultaneous consolidation were conducted by hot pressing (HP) method. Phase content of the obtained targets were established by XRD method after dry polishing. Superconducting characteristic of the obtained samples were measured by vibrational magnetometer. The superconducting transition with an onset at 39 K was observed in a good agreement with the results of the other groups obtained on samples prepared by conventional techniques. The phase exists near the nominal composition without a significant homogeneity range.

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Simple, reliable and scalable tool for the decoration of reduced graphene oxide (RGO) by iron oxide nanoparticles and the creation of polymer–RGO–Fe3O4 thin films are proposed. The composite is magnetically sensitive. Structural and microscopic studies and resistance measurements were performed. It has been found that these composites possess the hole-type conductivity.