Mössbauer Study of Nanocrystalline ε-Fe3−xCoxN System

Nanocrystalline e-Fe3−x Co x N system having particle size in the range of 10–15 nm is synthesized by chemical route. For compositions x = 0.0–0.2, the system crystallizes in hexagonal structure and for x = 0.4–0.8, the system shows a mixture of hexagonal e-Fe3−x Co x N and cubic α-Fe structures. The Mossbauer spectra shows the doublet for the former structure and the sextet for latter when cobalt concentration is in the range x = 0.4–0.8 indicating the presence of α-Fe trapped in the nitride matrix. The superparamagnetic nature of e-Fe3−x Co x N phase is confirmed from the magnetization measurements.