Size effect on the time dependence of magnetization of iron oxide particles

Author

Bottoni, Giancarlo

Author_Institution

Dipt. di Fisica, Ferrara Univ., Italy

Volume

33

Issue

5

fYear

1997

fDate

9/1/1997 12:00:00 AM

Firstpage

3049

Lastpage

3051

Abstract

The dependence of the thermal stability of the magnetization on the size of iron oxide particles is experimentally investigated, with measurements of the variation of the magnetization in presence of a reverse field. It is found that when the size of the particles decreases, the thermal stability of the magnetization is progressively weakened, with increase of magnetization decay, magnetic viscosity and fluctuation field and decrease of activation volume. The ratio between activation volume and mean physical volume of the particles increases when the particle size decreases, approaching unity for the smallest particles, which suggests an evolution of the magnetization switching mode with the size of the particles

Keywords

iron compounds; magnetic particles; magnetic recording; magnetisation; Fe₂O₃; activation volume; fluctuation field; magnetic viscosity; magnetization; magnetization decay; magnetization switching mode; mean physical volume; reverse field; size effect; thermal stability; time dependence; Fluctuations; Iron; Magnetic anisotropy; Magnetic field measurement; Magnetic switching; Magnetization; Particle measurements; Saturation magnetization; Size measurement; Thermal stability; Time measurement; Viscosity;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.617840

Filename

617840