Thermal decomposition of hydroxycarbonate Cu-Fe-Cr spinel precursors

Abstract

Abstract Decomposition of mixed Cu-Fe-Cr hydroxycarbonates was investigated by thermal analysis and in situ XRD and FTIR. TGA and DTA showed that increased preheating temperature removes modifying anions and decreases the spinel crystallization temperature. A disordered oxide phase containing carbonate is initially formed. The carbonate contents and crystallization temperature decreases depend on the Fe3+/Cr3+ ratio. The residual anion content may affect interlayer and interblock distances in this amorphous phase, changing the spinel crystallization temperature. Understanding the modifying anion effects on the spinel crystallization makes it possible to select the thermal treatment.