الخلاصة:
Abstract
In the present work the Cobalt-La ferrite has the general formula (CoLaxFe2-xO4) with x= (0000000.000000000.00020, 002.000.0) synthesized using sol-gel auto combustion as a modern chemical method .Nitrates, citric acid and ammonia used in order to get ferrite Nano powders at temperature (200 C). The obtained ferrite Nano powder calcined at different temperatures, 400 C, 000 C and 000 C for a period three hours, then sintered samples at temperature (0000 C).
The Structural, electrical and dielectric properties of Co-La ferrite studied by using FTIR, XRD, AFM, SEM and LCR-meter analysis. FTIR-spectra of CoLaFeO4 ferrite powders calcined at (400 C) showed the band around (000cm-0) and the other less than (400cm-0), confirming the metal-oxygen bond characteristic. XRD showed that the crystal size change from (...22nm) to (24.0.nm) at temperature (400 C) with increase La-ion content and the lattice constant change with increase La-ion content from (00.. Å) to (00.0 Å).
From SEM micrographs, cobalt ferrite at temperature (400 C) to sample x=000 and x=000.. It can be observed decrease in the particle shapes with increasing La-ion content. AFM figures proved the ferrite samples are homogeneous, and the particles are in the range of Nano-scale. It can be observed the average grain size change from (82000 nm to 002082 nm) with increasing concentration Lanthanum at temperature 4004 C).
The electric and dielectric properties were studied for all samples sintered at temperature (0000 C) by using LCR meter and the frequency range of (.0 Hz- .MHz).
AC Resistivity of all samples (sintered at 0000 C) have been measured as a function of frequency and found it decreases with increase in frequency. AC conductivity increases with frequency increase.
