Resumo:
The ceramics of the type ferrites are materials that present important characteristics of
electrical conduction and magnetic properties, as much as material magnetic hard, how much
of soft magnetic materials. The cubics ferrites of the espinel structure are oxides with
chemical formula MFe2O4, where M is a divalent metallic ion. Due to characteristic of the
espinel, diverse magnetic configurations are a gotten, depending on the occupation tax of the
magnetic ion (in general iron) in each sublattice. The diluted ferrites possess general formula
given for: MD2-xFexO4, where M and D are diamagnetics ions, being D the ion of substitution
doping and x is the concentration of ions of iron (0,002 ≤ x ≤ 0,350). The sample was
prepared using ceramics techniques in reaction of solid state and later they were submitted to
a magnetic characterization, electric and X-ray diffraction. The results of the magnetic
characterization were gotten by a magnetometer of vibrant sample (VSM) EG&G-Princeton
Applied Research, model 4500; the characterization for X-ray was used one X-ray
diffractometer, model URD 65; of the Seifert & with. Electrical measurements DC were
carried through with the use of a unit high-voltage measuring source - Keithley, model 237,
where the voltage applied in the samples varied of 0–40 V, the high temperatures. Two types
of contacts were used: the arrangement type "sandwich", being the inferior electrode the
proper door-sample, and the superior electrode with ring geometry and a silver was pasted on
both sides of the samples to ensure good electrical contact. The magnetic measurements
confirm its ferrite characteristics and in the electrical measurements, the electrical
conductivity indicated behavior of a semiconductor the high temperatures and the process of
electrical conduction termically presented to be activated
