Magnetic characteristics of ultrafine Fe particles reduced from uniform iron oxide particles

Authors

K. Bridger, Martin Marietta Laboratories, Martin Marietta Corporation, Baltimore, Maryland
J. Watts, Martin Marietta Laboratories, Martin Marietta Corporation, Baltimore, Maryland
M. Tadros, Martin Marietta Laboratories, Martin Marietta Corporation, Baltimore, Maryland
Gang Xiao, Johns Hopkins UniversityFollow
Sy_Hwang Liou, University of Nebraska-LincolnFollow
C.L. Chien, Johns Hopkins University

Date of this Version

4-15-1987

Comments

Published by American Institute of Physics. J. Appl. Phys. 61, 3323 (1987). ©1987 American Institute of Physics. Permission to use. Journal home page = http://jap.aip.org/jap/.

Abstract

Uniform, cubic 0.05-µm iron oxide particles were formed by forced hydrolysis of ferric perchlorate. These particles were reduced to α-Fe by heating in hydrogen at temperatures between 300 and 500 °C. The effect of reduction temperature and various prereduction treatments on the microstructure of the iron particles will be discussed. Complete reduction to α-Fe was established by ⁵⁷Fe Mössbauer spectroscopy and x-ray diffraction. Magnetic measurements on epoxy and polyurethane films containing these particles with various mass fractions gave coercivities as high as 1000 Oe. The relationship between the magnetic measurements and the microstructure will be discussed. Na₂SiO₃ is found to be the best coating material for the process of reducing iron oxide particles to iron.