Investigation of nickel ferrite formation in a binary Fe(III)-Ni(II) hydroxide precipitate containing H sub(2)O with or without Li sub(2)O doping

• Published in: Journal of alloys and compounds Vol. 486; no. 1-2; pp. 824 - 829
• Main Authors: Choi, Kwang-Soon, Yeon, Jei-Won, Park, Yang-Soon, Ha, Yeong-Keong, Han, Sun-Ho, Song, Kyuseok
• Format: Journal Article
• Language: English
• Published: 03.11.2009
• Subjects: Calcination; Differential thermal analysis; Doping; Hydroxides; Nickel ferrites; Particle size; Precipitates; Precipitation
• ISSN: 0925-8388
• DOI: 10.1016/j.jallcom.2009.07.074

The effects of calcination time, calcination temperature, particle size of the precursor precipitate, and Li sub(2)O doping on interactions within a mixed Fe(III)-Ni(II) hydroxide precipitate were investigated using thermogravimetry (TG), differential thermal analysis (DTA), and X-ray diffraction (XRD). The results indicated that neither the reaction time nor the particle size influenced the formation of nickel ferrite. It was found that the Fe(III) hydroxides participated in solid-solid interactions with the Ni(II) hydroxides to yield nickel ferrite at temperatures above 290 degree C. Increasing the percentage of Li sub(2)O dopant reduced the rate of nickel ferrite formation but increased that of nickel oxide formation, regardless of the calcination temperature between 400 and 700 degree C. These phenomena may be ascribed to the inhibition of crystallization of alpha -Fe sub(2)O sub(3) by the substitution of some Li super(+) ions into Fe sub(2)O sub(3) lattice structure.