Title :
The migration of Fe dopants in CrO2 particles
Author :
Bottoni, G. ; Candolfo, D. ; Cecchetti, A. ; Masoli, F. ; Corrieri, R.
Author_Institution :
Dept. di Phys., Ferrara Univ., Italy
fDate :
3/1/1988 12:00:00 AM
Abstract :
The effect of various thermal treatment on acicular CrO2 particles doped with Fe and Sb is analyzed. A weak thermal treatment (Tc) produces a reduction of the coercivity which is ascribed to a migration of Fe dopants from the bulk of the particle to the surface of the particle. A strong thermal treatment (T>Tc) enhances the Fe migration from the bulk to the surface and greatly reduces the coercivity and the Curie temperature. A successive weak annealing (Tc) gives rise to a partial recovery of lHc and Tc ascribed to a migration of Fe from the surface layer to the bulk of the particle. The activation energy for the Fe migration ranges from 0.3 to 0.8 eV.
Keywords :
Curie temperature; antimony; chromium compounds; coercive force; diffusion in solids; heat treatment; impurities; iron; magnetic properties of fine particles; CrO2:Fe,Sb; Curie temperature; Fe migration; coercivity; thermal treatment; Coercive force; Iron; Magnetic anisotropy; Magnetic hysteresis; Magnetosphere; Perpendicular magnetic anisotropy; Remanence; Saturation magnetization; Tail; Temperature;
Journal_Title :
Magnetics, IEEE Transactions on
