Structure and Properties of Magnetic Materials Fabricated by High Exothermic Processes

Over the past decade, significant development has been made in the preparation of powder materials ranging in size from nanometer to micrometer. Tuning and controlling the shape and size of the particles to receive desired electromagnetic properties of materials are highly important in emerging applications. In this research, we examined cost-effective methods to produce hard- and soft- magnetic, superparamagnetic, superconductive and multiferroic materials using highly exothermic processes including Carbon Combustion Synthesis of Oxides (CCSO), Solution Combustion Synthesis (SCS) and High Pressure Combustion Synthesis (HPCS). The feasibility of screen-printing process of hard magnetic ferrite nanoparticles produced by CCSO has been validated. By using SCS, fabrication of yttrium ferrite was demonstrated. Superconducting MgB2 doped with multi-walled carbon nanotubes and graphene produced by HPCS exhibited positive increment in critical current density. Furthermore, the investigation revealed that Bi2Te3, a well-known thermoelectric material, exhibits a transition from p to n-type conduction as a result of high-energy ball milling process. The transition is monitored over mechanical activation through measurement of the thermoelectric properties at the temperature range of 1.9 K and 390 K.