Thermal, structural and magnetic studies on chromite spinel synthesized using citrate precursor method and annealed at 450 and 650 °C

A facile in situ reduction route for preparation of spinel CoCr2O4polycrystalline nanosheets and their magnetic properties

“…Additionally, this method does not yield pure products easily because of the refractory nature of chromium(III) oxide and of many of the divalent-metal oxides involved. Recently, many other preparation strategies, such as sonochemical technique, 14 hydrothermal synthesis, 13,31,32 coprecipitation, 33 solution combustion method, 24,34 sol-gel route, 35,36 ignition of CoCr 2 O 7 •4C 5 H 5 N precursor, 37 thermolysis of polymer-metal complex, [38][39][40] co-assembly strategy with the assistance of the amphiphilic diblock copolymer 41 and so on, have been effectively engaged in the synthesis of CoCr 2 O 4 materials. As for the singlecrystalline CoCr 2 O 4 , the common growth methods include chemical vapor transport, 6,10,19,[42][43][44] flux technique, 16,45,46 and floating zone method.…”

Rapid calcination of ferrite Ni0.75Zn0.25Fe2O4 by microwave energy

“…Figure 2 shows the thermal analysis of Ni-Zn ferrite precursor powders. From the TG curve analysis, it was observed that the samples showed initial mass loss between 28 and 235°C for ferrite Ni 0.75 Zn 0.25 , which is assigned to the evaporation of volatile material, in particular evaporation of water coming from the dissolution of citric acid into water in the process of obtaining metal citrates, in addition to adsorbed gases [44]. A significant mass loss was observed from 254°C to 411.86°C, with a percentage of 76.75 % associated with the combustion of organic compounds and to the decomposition of nitrate wastes, which subsequently enabled the formation of oxides and crystallization of the material.…”