Moessbauer Study of Nanocrystalline ε-Fe_(3-x)Co_xN System

摘要

Nanocrystalline ε-Fe_(3-x)Co_xN 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 ε-Fe_(3-x)Co_xN and cubic α-Fe structures. The Moessbauer 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 ε-Fe_(3-x)Co_xN phase is confirmed from the magnetization measurements.