Particle size effects on the thermal behaviour of maghemite synthesised by flame pyrolysis

被引：18

作者：

Grimm, S

Stelzner, T

Leuthausser, J

Barth, S

Heide, K

机构：

[1] UNIV JENA,INST GEOWISSENSCH,D-07749 JENA,GERMANY

[2] UNIV JENA,INST ANORGAN & ANALYT CHEM,D-07743 JENA,GERMANY

来源：

THERMOCHIMICA ACTA | 1997年 / 300卷 / 1-2期

关键词：

carboxylate groups; maghemite; particle size effect;

D O I：

10.1016/S0040-6031(96)03127-9

中图分类号：

O414.1 [热力学];

学科分类号：

摘要：

Thermal treatment of pure nanoscale maghemite (gamma-Fe2O3) powders under argon yields different products depending on particle size. Particles with a mean diameter above 15 nm transform to hematite (alpha-Fe2O3). Smaller particles, which were synthesised under identical conditions but from solutions with lower Fe3+ concentrations, transform into magnetite (Fe3O4) during thermal treatment. This phenomenon can be explained by adsorbed or incorporated reducing carboxylate groups. The origin of the reducing species and possible reaction mechanisms with the maghemite particles are discussed. (C) 1997 Elsevier Science B.V.

引用

页码：141 / 148

页数：8