57Fe Mössbauer study of La0.67Ca0.33Mn1 − xFexO3 CMR system

Fe-doped polycrystalline samples La0.67Ca0.33Fe x Mn1 − x O3 (x = 0%, 5%, 7.5%, 10% and 15%) are studied employing 57Fe Mossbauer effect measurements. The room temperature Mossbauer measurements of all the samples indicate the presence of Fe + 3 state and it is observed that the quadrupole splitting remains constant up to 10% Fe doping and increases with 15% Fe doping. Resistivity data shows increasing insulating behaviour with Fe doping and insulating region follows Efros–Shlovskii variable range hoping model.