Annealing study of Fe2O3 nanoparticles:: Magnetic size effects and phase transformations

被引：84

作者：

Xu, XN ^{[1
]}

Wolfus, Y

Shaulov, A

Yeshurun, Y

Felner, I

Nowik, I

Koltypin, Y

Gedanken, A

机构：

[1] Bar Ilan Univ, Dept Phys, IL-52900 Ramat Gan, Israel

[2] Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel

[3] Bar Ilan Univ, Dept Chem, IL-52900 Ramat Gan, Israel

[4] Nanjing Univ, Dept Phys, Nanjing 210093, Peoples R China

来源：

JOURNAL OF APPLIED PHYSICS | 2002年 / 91卷 / 07期

关键词：

Hematite - Nanoparticles - Phase transitions - Magnetic properties - Particle size - Synthesis (chemical) - Annealing - Nanomagnetics;

D O I：

10.1063/1.1457544

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

Sonochemically synthesized Fe2O3 nanoparticles were annealed in air or in vacuum while their magnetization was continuously recorded. Annealing in vacuum at temperatures T-a between 240 and 450 degreesC produced nanophases of gamma-Fe2O3 with average particle size ranging from 4 to 14 nm, depending on T-a. Phase transformation into alpha-Fe2O3 occurred directly by annealing in air, or via an intermediate Fe3O4 phase by annealing in vacuum at temperatures higher than 450 degreesC. Mapping the correlation between the magnetic properties and the annealing conditions, enables control of the annealing process to obtain nanocrystals of gamma-Fe2O3, alpha-Fe2O3, or Fe3O4 with different particle size and magnetic properties. (C) 2002 American Institute of Physics.

引用

页码：4611 / 4616

页数：6

共 22 条

[1] A new inexpensive method for the preparation of acicular precursors for magnetic recording media [J].