Preparation and characterization of Hydroxyapatite-Barium Titanate Composite

Abstract

The present work deals with the synthesis and characterization of hydroxyapatite- barium titanate composite. The composites have been prepared varying the barium titanate amount in the range of 10- 40 weight% in the hydroxyapatite matrix. The barium titanate powders used in this study has been prepared following solid state synthesis technique, followed by the grinding in a pot mill. The synthesized barium titanate powders have been characterized using X-ray diffraction, particle size analysis and isoelectric point measurements. A stabilized barium titanate suspension has been prepared using Darvan-C polyelectrolyte at basic pH.
Calcium nitrate tetrahydrate (Ca(NO3)2. 4H2O ) and di-ammonium hydrogen phosphate ((NH4)2HPO4) have been used as precursors for calcium (Ca2+) and phosphate ((PO4)3-) ions respectively, which were then precipitated over the stabilized barium titanate suspension. The suspension has been allowed to settle, washed with cold water and calcined to obtain the composite powders. The synthesized hydroxyapatite-barium titanate composites have been characterized using X-ray diffraction and dilatometry. The synthesized composite powders have been pelletized and sintered at three different temperatures. The sintered pellets have been characterized using bulk density, shrinkage and X-ray diffraction measurements. The pellets are coated with silver paste and have been characterized for their dielectric behavior using a dielectric interface.