DocumentCode :
847019
Title :
Yttrium iron garnet heterocoagulated by silica
Author :
Godoi, Ricardo H M ; Marques, Rodrigo F C ; Varanda, Laudemir C. ; Jafelicci, Miguel, Jr.
Author_Institution :
Antwerp Univ., Belgium
Volume :
38
Issue :
5
fYear :
2002
fDate :
9/1/2002 12:00:00 AM
Firstpage :
2625
Lastpage :
2627
Abstract :
Coated purpose of homogeneous distribution as a second phase is introduced in magnetic systems. Yttrium iron garnet (YIG) shows special interest as magnetic dye, microwave absorber, and magnetic fluids when heterocoagulated by other material. Surface and interface magnetic properties are intimately connected with the new properties of the silica on YIG system. Neel first introduced the concept of surface anisotropy, and Chen el al. developed a model that describes the anisotropy effects at the boundary surface particle, which was applied in this work. Spherical YIG particles were prepared by coprecipitation method and coated with silica using the tetraethylorthosilicate (TEOS) hydrolysis process. The silica-YIG boundary was investigated by transmission electron microscopy. Hysteresis loops comparatively show the profile of the naked and silica-covered YIG particles. The surface anisotropies were calculated using the Chen et al. approach. Indeed, in heterocoagulation systems, the surface anisotropy is a result of the interface symmetry breaking, as observed.
Keywords :
X-ray photoelectron spectra; coagulation; coercive force; garnets; magnetic anisotropy; magnetic hysteresis; magnetic particles; particle size; precipitation (physical chemistry); surface magnetism; transmission electron microscopy; yttrium compounds; X-ray photoemission; YFe5O12; YFe5O12-SiO2; YIG; YIG-SiO2; average particle size; coercive field; coprecipitation method; heterocoagulation by silica; homogeneous distribution; hysteresis loops; interface magnetic properties; interface symmetry breaking; magnetic dye; magnetic fluids; magnetic particles; microwave absorber; second phase; spherical particles; surface anisotropy; tetraethylorthosilicate hydrolysis; thin silica cover; transmission electron microscopy; Anisotropic magnetoresistance; Garnets; Iron; Magnetic anisotropy; Magnetic liquids; Magnetic materials; Magnetic properties; Perpendicular magnetic anisotropy; Silicon compounds; Yttrium;
fLanguage :
English
Journal_Title :
Magnetics, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9464
Type :
jour
DOI :
10.1109/TMAG.2002.801964
Filename :
1042292
Link To Document :
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