Synthesis and ac properties of mixed li-zn ferrites

The mixed polycrystalline ferrites 〖Li〗_0.5(1-x) 〖Zn〗_x 〖Fe〗_(2.5-0.5x) O_4 were prepared by the conventional solid state method using high purity metal oxides ZnO,〖Fe〗_2 O_3 and LiCO_3for different concentration of Zn2+ions. Double probe electrode method was used to study the AC properties: the AC electrical conductivity (σ), the dielectric constant: real(ε'), imaginary (ε'') and complex (ε*), and the dielectric loss tangent (tan δ) over therange of the appliedfrequency (f=1 KHz-5 MHz)at room temperature. σincreased exponentially with the increasing f where the maximum value was for the sample 〖Li〗_0.3 〖Zn〗_0.4 〖Fe〗_2.3 O_4. The obtained results of the dielectric parameter (ε', ε'', ε* andtan δ), also, decreased exponentially with increasing f, which confirmsthe normal spinel ferrite behavior. The behavior of AC propertiescan be elucidated on the basis of the exchanged electrons between . The obtained results reveal that the AC properties change by substitution of the Zn2+ionsin Li-spinel ferrite matrix.