Correlation between the nanocrystalline Sm(Fe,Mo)12 and its out of equilibrium phase Sm(Fe,Mo)10

•A study of the structure and magnetic properties of SmFeMo compound.•A new out of equilibrium P6/mmm-type structure was found.•Correlation between the 1/12 phase and its out of equilibrium 1/10 phase.

Nanostructured Sm–Fe–Mo semi-hard magnetic material exhibiting enhanced magnetic properties can be produced by ball milling followed by recrystallization. Milled samples were annealed for 30 min in a vacuum at different temperatures (TA) between 700 and 1190 °C. The effects of heat treatment and Mo content on structural and magnetic property changes have been investigated by means of X-ray diffraction using the Rietveld method, transmission electron microscopy and magnetic measurements. For samples annealed at TA>900°C the tetragonal ThMn12-type structure is identified, while for 7005kOe) has been observed for the new hexagonal P6/mmmP6/mmm phase suggesting that nanocrystalline Sm(Fe,Mo)10, is a semi-hard material, and is potential candidate for magnetic recording.