DISPERSION OF DIELECTRIC-CONSTANT OF OXYGEN-DEFICIENT COPPER FERROSPINEL

Both copper and lithium ions can be used to generate deficiency. The m aterials (1)CuFe2O4,(2)CuFe2O4: CuO and (3)CuFe2O4: 0.75 LiAlH4 have b een synthesized by usual ceramic technique. Dispersion of dielectric c onatant and tan delta of these samples have been studied in the freque ncy range from 400 Hz to 1 MHz. The dispersion is in accordance with K oop's model. The oxygen deficient copper ferrospinel exhibit larger di electric constants and tan delta values compared to CuFe2O4. The plot of relative loss factor versus relative dielectric constant indicates distribution of relaxation time in the range 140 mu s - 300 mu s arisi ng out of and suggests heterogeneities interfacial polarisation On the basis of these results, it is concluded that the existance of(Cu+1, C u+2) and (Fe+2, Fe+3) ionic pairs, oxygen deficiency and availability of vacant sites in a spinel structure contribute to interfacial polari sation.