Investigation of the structural and electrical properties of Al-Ni the ferrite and effect of Yttrium

Abstract

The aim of the present work is to prepare some samples of the S-type spinel ferrite Al0.51-0.51x Nix Fe2.16-0.16x O4 and Al0.51-0.51x Nix Fe2.06-0.16xY0.1O4 where (x = 0.0, 0.5, and 1) to investigate some of their structure and different electric properties as a function of temperature, frequency and compositions. The X-ray diffraction analysis of the samples ensures the formation of S-type spinel ferrite with the average particle size estimated as 35.1-35.9nm. Ac conductivity, dielectric constant and loss tangent were investigated by using the complex impedance technique. The conductance results specified two types of conduction mechanisms, hopping conduction and displacement conduction of charge carriers quantum-mechanical-tunneling, QMT and correlated barrier hopping, CBH in the studied range of temperature. Cole-Cole diagrams show as expected the existence of a distribution of relaxation times and gave values of the activation energy of the dielectric relaxation process ranging from -0.022eV to 0.173eV.