Hyperfine parameters, (ac and dc) conductivity, and dielectric relaxation studies of CuAlFeO4, using Mossbauer and adaptive technique for electrical measurements

Single-phase cubic spinel ferrite CuAlFeO4 has been synthesized. Hyperfine parameters have been investigated with (57) Fe Mossbauer effect (ME) spectroscopy in the temperature range (77-345 K). The obtained cation distribution revealed an inverse spinel system. The determined magnetic transition and Debye temperature theta(D) are 340 and 233 K, respectively. The temperature dependence of the sublattice magnetization sigma(s) (T) obeys a one-third power law in the temperature range (170-339 K). The electrical properties have been investigated, using adaptive technique with cell designed for measuring both ac and dc conductivity simultaneously. This enables the separation of the dc and ac components of the electrical conductivity where the conduction mechanism is determined. In addition, the relation of the dielectric loss tan 3 with frequency at different temperatures shows relaxation spectra where the relaxation time and the maximum frequency of the hopping conduction mechanism are determined. (C) 2004 Elsevier B.V. All rights reserved.