FIZIKA A 3 (1994) 1, 25-33

ELECTRICAL AND THERMOELECTRICAL PROPERTIES OF PURE AND SUBSTITUTED COPPER FERRITES

MOHAMED A. AHMED, MOHAMED A. EL-HITI and MOHAMED E. EL-SHABASY^*
Physics Department, Faculty of Science, Tanta University, Tanta, Egypt
^* Physics Department, Faculty of Science, El-Minia University, El-Minia, Egypt

Received 21 January 1994

Revised manuscript received 22 March 1994

Samples of the CuFe_2-xAl_xO₄ system with x=0, 0.2, 0.4 and 0.6 were prepared. The single phase spinel structure was verified by X-ray diffraction method. The thermoelectric power (a) and dc electrical resistivity (r) were studied as a function of temperature and composition. The results show that the resistivity increases and the transition temperature decreases with increasing the aluminium substitution. The activation energy in ferrimagnetic region is lower than that in paramagnetic region. The drift mobility of carriers increases exponentially with temperature as expected for ferrites.

UDC 538.93
PACS 72.15.Eb, 72.15.Jfx

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