title: Structure, microstructure, and magnetism in ferrimagnetic bioceramics.
abstract: The structural and magnetic properties of ferrimagnetic bioglass ceramics in the system [0.45(CaO,P2O5)(0.52 - x)SiO2 xFe2O3 0.03Na2O], x = 0.05, 0.10, 0.15, 0.20 and heat-treated at the temperature range 600-1100 degrees C are assessed. The structure and microstructure of the samples are characterized with X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Calcium phosphate and magnetite develop as the two major crystalline phases. For x = 0.10 and 0.20, calcium phosphate undergoes a gradual transition from the monoclinic to the rhombohedral crystal system (SG P21/a-->R3c) as the heat-treatment temperature increases from 800 to 1100 degrees C. Dendrites of iron oxide with crystallites of various sizes are observed to form within a glassy matrix enriched in calcium, phosphorous, and silicon. Saturation magnetization, remanence, and coercivity are found from dc magnetic measurements. They vary with the specific processing parameters of the composites, and these are correlated with the observed structure and microstructure of the materials.
authors.affiliation: Physics Department, Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33431, USA. leventou@fau.edu
authors.forename: Th
authors.initials: T
authors.lastname: Leventouri
authors.forename: A C
authors.initials: AC
authors.lastname: Kis
authors.forename: J R
authors.initials: JR
authors.lastname: Thompson
authors.forename: I M
authors.initials: IM
authors.lastname: Anderson
mesh_terms: D001672:Biocompatible Materials / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects; D002516:Ceramics / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects; D004574:Electromagnetic Fields; D005290:Ferric Compounds / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects; D008280:Magnetics; D008422:Materials Testing; D008968:Molecular Conformation; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D005290:Ferric Compounds; C000499:ferric oxide