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Materials Research

Print version ISSN 1516-1439

Abstract

MIR, Mirta et al. XRD, AFM, IR and TGA study of nanostructured hydroxyapatite. Mat. Res. [online]. 2012, vol.15, n.4, pp. 622-627.  Epub July 03, 2012. ISSN 1516-1439.  http://dx.doi.org/10.1590/S1516-14392012005000069.

In this work, the synthetic hydroxyapatite (HAP) was studied using different preparation routes to decrease the crystal size and to study the temperature effect on the HAP nano-sized hydroxyapatite crystallization. X-ray diffraction (XRD) analysis indicated that all samples were composed by crystalline and amorphous phases . The sample with greater quantity of amorphous phase (40% of total mass) was studied. The nano-sized hydroxyapatite powder was heated and studied at 300, 500, 700, 900 and 1150 °C. All samples were characterized by XRD and their XRD patterns refined using the Rietveld method. The crystallites presented an anisotropic form, being larger in the [001] direction. It was observed that the crystallite size increased continuously with the heating temperature and the eccentricity of the ellipsoidal shape changed from 2.75 at 300 °C to 1.94, 1.43, 1.04 and 1.00 respectively at 500, 700, 900 and 1150 °C. In order to better characterize the morphology of the HAP the samples were also examined using atomic force microscopy (AFM), infrared spectrometry (IR) and thermogravimetric analysis (TGA).

Keywords : nanocrystals; AFM; XRD; hydroxyapatite; Rietveld; TGA e IR.

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