TITLE:
Direct Preparation of the Nanocrystalline MnZn Ferrites by Using Oxalate as Precipitant
AUTHORS:
Fei Hua, Cuicui Yin, Huanque Zhang, Qiangqiang Suo, Xin Wang, Huifen Peng
KEYWORDS:
Magnetic Material, MnZn Ferrite, Co-Precipitation Process, Nanocrystalline Material
JOURNAL NAME:
Journal of Materials Science and Chemical Engineering,
Vol.3 No.12,
December
17,
2015
ABSTRACT: Oxalate was generally used as a precipitant
for synthesis of MnZn ferrites during the co-precipitation process. However,
the MnZn ferrite couldn’t be directly obtained and a calcination process was
needed. In this research, we reported a direct preparation of the MnZn ferrite
nanoparticles by using co-precipitation method, together with refluxing
process. XRD measurements proved that crystallite size of the obtained samples
increased with an increase in pH value of the co-precipitation solution, and
that the crystallite size of about 25 nm was obtained for the sample at a pH of
13. This sample showed the maximum Ms of 58.6 emu/g, which was about one times
larger than that of 12 (pH value). Calcination to the obtained samples result
in an enlargement in their crystal size and an improvement in their magnetic
properties with an increase in temperatures. The samples calcinated in CO2 + H2 atmosphere presented good stability, and the maximum Ms value of 188.2 emu/g
was obtained for the 1100。C-heated sample. Unfortunately, precipitation of some
Fe2O3 at 800。C suggested poor stability of the nanocrystalline MnZn ferrite in
N2 atmosphere.