Substitution of manganese and iron into hydroxyapatite: Core/shell nanoparticles

Journal Article · Mon Aug 04 04:00:00 EDT 2008 · Materials Research Bulletin

DOI:https://doi.org/10.1016/j.materresbull.2007.09.004· OSTI ID:21144076

Pon-On, Weeraphat; Meejoo, Siwaporn ^[1]; Tang, I -Ming ^[2]

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1. Department of Chemistry, Faculty of Science, Mahidol University, Bangkok 10400 (Thailand)
2. Department of Physics, Faculty of Science, Mahidol University, Institute of Science and Technology for Research and Development, Salaya Campus, Mahidol University, Nakorn Pathom 71730 (Thailand)

The bioceramics, hydroxyapatite (HAP), is a material which is biocompatible to the human body and is well suited to be used in hyperthermia applications for the treatment of bone cancer. We investigate the substitution of iron and manganese into the hydroxyapatite to yield ceramics having the empirical formula Ca{sub 9.4}Fe{sub 0.4}Mn{sub 0.2}(PO{sub 4}){sub 6}(OH){sub 2}. The samples were prepared by the co-precipitation method. The formation of the nanocrystallites in the HAP structure as the heating temperatures were raised to obtain a glass-ceramic system are confirmed by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron diffraction (ED) and electron spin resonance (ESR). TEM images show the core/shell structure of the nanoparticles, with the core being formed by the ferrites and the shell by the hydroxyapatite. The ED patterns indicate the nanoparticles formed at 500 deg. C have an amorphous structure while the nanoparticles formed at 1000 deg. C are crystalline. ESR spectroscopy indicated that the Fe{sup 3+} ions have a g-factor of 4.23 and the Mn{sup 2+} ions have a g-factor of 2.01. The values of the parameters in the spin Hamiltonian which describes the interaction between the transition metal ions and the Ca{sup 2+} ions, indicate that the Mn{sup 2+} ion substitute into the Ca{sup 2+} sites which are ninefold coordinated, i.e., the Ca(1) sites.

• OSTI ID: 21144076
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 8-9 Vol. 43; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
APATITES
CALCIUM COMPOUNDS
CALCIUM IONS
CERAMICS
COPRECIPITATION
ELECTRON DIFFRACTION
ELECTRON SPIN RESONANCE
HAMILTONIANS
HYPERTHERMIA
IRON COMPOUNDS
IRON IONS
LANDE FACTOR
MANGANESE COMPOUNDS
MANGANESE IONS
MICROSTRUCTURE
NANOSTRUCTURES
NEOPLASMS
PARTICLES
PHOSPHATES
SCANNING ELECTRON MICROSCOPY
SPECTROSCOPY
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION