A study of the magnetic after-effect in W-hexagonal compounds

Author

de Francisco, C. ; Muñoz, J.M. ; Torres, R. ; Torres, L. ; Iñiguez, J. ; Zazo, M.

Author_Institution

Dept. Electr. & Electron., Valladolid Univ., Spain

Volume

29

Issue

6

fYear

1993

fDate

11/1/1993 12:00:00 AM

Firstpage

3523

Lastpage

3525

Abstract

The relaxation of the initial permeability is measured in barium ferrite samples with W-hexagonal structure. In the temperature range between 80 and 420 K three clear relaxation processes are found; these features are influenced by sintering temperature and atmosphere. Peak C (370 K) seems to arise from long range cation diffusion processes via vacancies, with activation energies around 1.1 eV. Peak B (300 K) can be attributed to local rearrangements of ferrous cations in octahedral position via lattice vacancies and can be fitted by the superposition of two Debye processes with activation energies close to 0.80 and 0.84 eV. Peak A exhibits the characteristics of a single Debye process with an activation energy on the order of 0.48 eV and its origin is not yet clear

Keywords

barium compounds; ferrimagnetic properties of substances; ferrites; magnetic aftereffect; magnetic permeability; magnetic relaxation; 80 to 420 K; BaFe₁₈O₂₇; Debye processes; W-hexagonal compounds; W-hexagonal structure; activation energies; ferrous cations; initial permeability; lattice vacancies; local rearrangements; long range cation diffusion processes; magnetic after-effect; octahedral position; relaxation processes; sintering temperature; temperature range; Amorphous magnetic materials; Atmosphere; Demagnetization; Diffusion processes; Ferrimagnetic materials; Ferrites; Lattices; Magnetic domain walls; Permeability measurement; Temperature distribution;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.281217

Filename

281217