**1.2. High energy ball milling**

The use of mechanical milling in the preparation of inorganic materials (ceramics, metals, and alloys) has a long tradition. It is a cheap and relatively rapid method that, in some cases, guarantees the formation of the desired compounds without the need of other thermal treatment. The tuning of ferrites nanoparticles could be obtained by changing milling container, speed, time, ball-to-powder weight ratio, extent of filling the vial, milling atmosphere, presence of a process control agent, temperature of milling, etc. [9].
