الفهرس 
Introduction and Aim of the WorkOnly 14 pages are availabe for public view
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Abstract
Nano-crystalline copper ferrite (220 nm) was obtained by a novel self-flash combustion of a homogeneous mixture of one mole copper (II) acetate monohydrate, Cu(CH3COO)2.H2O and two moles of iron (III) acetate basic, Fe(CH3COO)2.OH. The powder mixture is then heated directly on a hot plate allowing the decomposition of acetates mixture. The powder is then fired at 1000 oC for 6 hours to ensure the complete conversion of the precursors to the copper ferrite phase which achieved 220 nm sized crystals.
The ferrite powder (220 nm) was activated mechanochemically by ball milling for 10, 20, 40 and 100 hours in order to obtain smaller crystallite size. 134, 89, 50 and 99 nm crystals were obtained respectively and correlated to the enhancement in magnetic properties. The ferrite powders was pressed in the form of compacts of 1 cm diameter and 0.4 cm thickness, dried at 100 oC for 24 hours and fired at 600 oC for 2 hours just to obtain compact discs.
Nano-crystalline (220 nm) CuFe2O4 compacts were isothermally reduced in H2 flow (1l/min.) at 300–600 oC prior to the formation of metallic Cu and Fe. The isothermal reduction profiles obtained in this study show a topochemical mode of reduction, by which the reduction process proceeds. The activation energy values for the reduction process through the initial, intermediate and final stages of reduction were calculated from Arrhenius equation. CO2 was allowed to flow and decompose to carbon nano-tubes directly over the nano-wires metallic phase of iron and copper, freshly produced from the complete reduction of CuFe2O4 at 400–600 oC. The prepared, completely reduced and reoxidized CuFe2O4 compacts, were characterized by XRD, TEM, SEM and reflected light microscope. For the reoxidation process, it is found that the reduction temperature as well as the reoxidation temperature affected the rate of reoxidation process through its different stages as the reduction process affects the porosity and reactivity of the compacts.
In order to study the effect of the crystalline size on the reduction and reoxidation kinetics, nano-crystalline (50 nm) CuFe2O4 compacts were isothermally reduced in H2 flow (1l/min.) at 400-600 oC and reoxidized directly in CO2 flow at 400-600 oC. The obtained results were then compared with those obtained with the bigger sized crystals.