Study of the correlation between electrical and magnetic properties of phase separated manganites using a General Effective Medium approach

JOAQUIN SACANELL; MARIANO QUINTERO; FRANCISCO PARISI; LUIS GHIVELDER; ANA GABRIELA LEYVA; PABLO LEVY

Buenos Aires, Argentina

Conferencia; “At the frontiers of condensed matter”, FCM2006; 2006

Centro Atómico Constituyentes, Comisión Nacional de Energía Atómica

We have performed electrical resistivity and DC magnetization measurements as a function of temperature, on polycrystalline samples of phase separated La5/8-yPryCa3/8MnO3 (y = 0.3). We have used the General Effective Medium Theory to obtain theoretical resistivity vs. temperature curves corresponding to different fixed ferromagnetic volume fraction values, assuming that the sample is a mixture of typical metallic – like and insulating manganites. By comparing this data with our experimental resistivity curves we have obtained the relative ferromagnetic volume fraction of our sample as a function of temperature. This result matches with the corresponding magnetization data in excellent agreement, showing that a mixed phase scenario is the key element to explain both the magnetic and transport properties in the present compound