STRUCTURAL, ELECTRICAL AND SPECTROSCOPIC STUDIES OF THE SYSTEM NI1-XCUUXFE2O4

Data are presented on the d.c. conductivity, x-ray analysis and infra- red spectroscopy of the system Ni1-xCuxFe2O4, particularly as a functi on of the copper content. Electrical conductivity measurements reveale d that the activation energy for conductivity decreases with increasin g copper content. The mobility of holes calculated from infra-red meas urements corresponds to the values from the conductivity data. From x- ray diffraction analysis and electrical conductivity measurements, it may be concluded that in the system Ni1-xCuxFe2O4, Ni2+ and Fe2+ are f ound at octahedral sites and Cu2+ at tetrahedral sites. Comparison of these measurements is made with the data obtained on the Zn1-xCuxAl2O4 system.