Nanostructured single domain epsilon-Fe3N particles have been prepared by chemical route. Magnetic dipolar interaction among particles has been observed. The FC and ZFC magnetization curves show the superparamagnetic blocking temperature around 125 K, at low applied field of 0.005 T. At higher applied field, these ZFC and FC magnetization curves merge because of increase in magnetization energy that overcomes the magnetic anisotropy and dipolar interaction energies. Mossbauer spectroscopy further corroborates the superparamagnetic nature at 300 K. (C) 2007 Elsevier Ltd. All rights reserved.