Title :
Manganese location and magnetic properties of the Sr(Ba)Mn2Fe16O27 W-type hexagonal ferrite
Author :
Collomb, A. ; Litsardakis, G. ; Mignot, J.P. ; Samaras, D.
Author_Institution :
Lab. de Cristallogr., CNRS, Univ. Sci. Technol. et Med. de Grenoble, France
fDate :
3/1/1988 12:00:00 AM
Abstract :
The Sr(Ba)Mn22+Fe163+O27 W-type hexagonal ferrites were prepared. These two compounds are ferrimagnetic. Their Curie temperatures are approximately 430 degrees C; at room temperature, their magnetizations and magnetic anisotropy fields are approximately 73 emu/g and approximately 12 kOe respectively. By neutron diffraction on the powder sample of SrMn2Fe16O27, the Mn location and the magnetic structure are determined: the Mn cations lie mainly in the tetrahedral sites of the S blocks and all the magnetic moments are along the hexagonal c axis. Permanent magnetic devices were prepared: the variations of the density, the remanence, and the coercive force as a function of the sintering temperature are given. The best values obtained are: Br=2500 G and HcJ=3000 Oe.
Keywords :
Curie temperature; barium compounds; coercive force; crystal atomic structure of inorganic compounds; ferrites; magnetic anisotropy; magnetic structure; magnetisation; manganese compounds; neutron diffraction examination of materials; permanent magnets; remanence; sintering; strontium compounds; 20 degC; 430 degC; BaMn2Fe16O27; Curie temperatures; Mn cations; Mn location; S blocks; SrMn2Fe16O27; W-type hexagonal ferrite; coercive force; density; ferrimagnetic; hexagonal c axis; magnetic anisotropy fields; magnetic moments; magnetic properties; magnetic structure; magnetizations; neutron diffraction; permanent magnets; powder sample; remanence; sintering temperature; tetrahedral sites; Diffraction; Ferrimagnetic materials; Ferrites; Iron; Magnetic anisotropy; Magnetic properties; Manganese; Neutrons; Perpendicular magnetic anisotropy; Temperature;
Journal_Title :
Magnetics, IEEE Transactions on
