SURFACE POTENTIAL MEASUREMENT OF ELECTRICALLY POLED HAP CERAMICS

The surface morphology and surface potential of the hydroxyapatite (HAp) ceramics with and without electrically poling were first investigated by tapping mode atomic force microscopy (TMAFM) combined with surface potential microscopy (SPoM). The HAp ceramic specimens were prepared by sintering the compact bodies of wet-chemically synthesized powders at 1250°C for 2 h under H₂O flow. The specimen was partially polarized in a do field of 1000 V cm⁻¹ for 1 h in air at 300°C. The surface potential distribution on the HAp specimen were significantly different between unpolarized surface and polarized one; the surface potential of polarized HAp region was higher than that of unpolarized one. The acceleration and deceleration of in vitro bonelike crystal growth on HAp ceramics soaking in a simulated body fluid solution could be related to the surface potential change caused by the electrically poling.