Influence of Fe3+ on perovskite oxides: La2/3Ca1/3Mn1-xFexO3

The structure and magnetoresistance properties in sintered samples of La-2/ 3 Ca-1/3 Mn1-x FexO3 (0 less than or equal to x less than or equal to 0.84) are studied by using Mossbauer spectroscopy, XRD and magnetic measurement. There are antiferromagnetic interactions between Fe and its nearest neighb ors (Fe, Mn) when 0 less than or equal to x less than or equal to 0.67, whi ch are important factors influencing the double-exchange between Mn3+ and M n4+, Curie temperature, magnetic moment and GMR. It is suggested that the M n3+(Fe3+)/Mn4+ system also consists of magnetic clusters with different siz es.