Manganese ferrite synthesized from Mn(II) acetate plus hematite freeze-dried powders

被引：19

作者：

Bellini, J. V. ^{[1
]}

de Medeiros, S. N. ^{[1
]}

Ponzoni, A. L. L. ^{[1
]}

Longen, F. R. ^{[1
]}

de Melo, M. A. C. ^{[1
]}

Paesano, A., Jr. ^{[1
]}

机构：

[1] Univ Estadual Maringa, Dept Fis, BR-87020900 Maringa, Parana, Brazil

来源：

MATERIALS CHEMISTRY AND PHYSICS | 2007年 / 105卷 / 01期

关键词：

freeze-drying; manganese ferrite; thermal analysis; Mossbauer spectroscopy;

D O I：

10.1016/j.matchemphys.2007.04.005

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Freeze-drying was used to obtain a homogeneous fine powder containing (CH3COO)(2)Mn-2H2O and ct-Fe2O3 (molar ratio Fe:Mn = 3: 1), which was thermally treated for 2 h in N-2 atmosphere, at 400 degrees C. This composite system was further annealed for 4 h in the same atmosphere, either at 700 degrees C or at 1000 degrees C. The 700 degrees C annealed sample was thermally treated in air at 1200 degrees C and then rapidly quenched. The phase transformations that occurred in the freeze-dried and heat-treated powders were investigated by thermal analyses, X-ray diffractometry, scanning electron microscopy and Mossbauer spectroscopy. Results showed that MnO-alpha-Fe2O3-Fe3O4 compounds were obtained after the first heat-treatment. Samples subsequently annealed in N atmosphere revealed the formation of Fe-rich manganese ferrites and manganowUstite phases. However, a single spinel phase was obtained for the sample that had been annealed and quenched in air. (c) 2007 Elsevier B.V. All rights reserved.

引用

页码：92 / 98

页数：7

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