Electrical Transport Properties of Bisub2/subOsub3/sub-Doped CoFesub2/subOsub4/suband CoHosub0.02/subFesub1.98/subOsub4/subFerrites

摘要

Two series of CoHoxFe2-x O4 (x = 0.0,0.02) ferrites with Bismuth oxide doping from (0.1-0.3)% were prepared by Co-precipitation technique. X-ray diffraction analysis revealed fcc structure. The lattice constants were found to decrease as the doping of Bi2O3increases in both series. An increase in Bismuth oxide concentration from (0.1-0.3%) in CoFe2O4, and CoHo0.02Fe1.98O4ferrites leads to an increase in room temperature resistivity. Temperature dependent resistivity decreases as the temperature increases following the Arrhenius equation. The activation energy increases with the increase of Bi2O3-concentration for both CoFe2O4 and CoHo0.02Fe1.98O4series. The frequency dependant dielectric constant follows the Maxwell-Wagner type interfacial polarization. The dielectric loss indicates the normal behavior of these ferrites. SEM analysis shows an increase in grain size with increasing Bismuth concentration.