57Fe Mössbauer study of La0.67Ca0.33Mn1 − x Fe x O3 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 Mössbauer effect measurements. The room temperature Mössbauer 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. [ABSTRACT FROM AUTHOR]