  The FeRh alloy is an attractive material for studies of magnetic first-order
phase transitions. The phase transition in FeRh from an antiferromagnetic to
the ferromagnetic state is accompanied by the nucleation, growth, and merging
of ferromagnetic clusters. The ferromagnetic phase evolution is studied in
detail, and its various stages are distinguished. Both static properties and
phase transition kinetics (time dependences of magnetization) are investigated.
A comprehensive analysis allows us to determine the ferromagnetic phase
nucleation regions and the main features of phase growth. In addition, the
mechanisms that lead to a change in the ferromagnetic phase growth rate (the
limitation effect and the magnetocaloric effect) were determined. The variation
of phase transition evolution dominant mechanisms depending on the sample
microstructure was shown.
