Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5458619 | Journal of Alloys and Compounds | 2017 | 38 Pages |
Abstract
The impact of ultra-short milling at liquid nitrogen temperatures on structural and magnetic properties of cobalt ferrite (CoFe2O4) powders has been explored for the first time. Cryomilling for only up to 9 min increases the coercivity of the isotropic powder from 139 to 306 kA/m (1.74-3.85 kOe) and results in its modifications comparable with milling for hours at room temperature. A thermal treatment of processed CoFe2O4 enables further optimization of powder magnetic properties and leads to a high value of energy product (13.5 kJ/m3) for the sample treated at 600 °C. Systematic studies, comprising analysis of structural and microstructural properties, based on synchrotron powder X-ray diffraction, scanning and transmission electron microscopy demonstrate the high efficiency of cryomilling in reduction of crystallite sizes and formation of lattice strain in the processed cobalt ferrite samples.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
Matylda N. Guzik, Karol M. GolasiÅski, F. Javier Pedrosa, Petra JenuÅ¡, Alberto Bollero, Bjørn C. Hauback, Stefano Deledda,