The influence of thermal annealing on structure and oxidation of iron nanowires

Raman spectroscopy as well as Mossbauer spectroscopy were applied in order to study the phase com- position of iron nanowires and its changes, caused by annealing in a neutral atmosphere at several temperatures ranging from 200°C to 800°C. As-prepared nanowires were manufactured via a simple chemical reduction in an external magnetic fi eld. Both experimental techniques proved formation of the surface layer covered by crystal- line iron oxides, with phase composition dependent on the annealing temperature (Ta). At higher Ta, hematite was the dominant phase in the nanowires.