Figure 5. The 3D images of elemental mapping analysis of the hydroxyapatite (HAp) samples, oxygen Figure 5. The 3D images of elemental mapping analysis of the hydroxyapatite (HAp) samples, oxygen Figure 5. The 3D images of elemental mapping analysis of the hydroxyapatite (HAp) samples, oxygen Figure 5. The 3D images of elemental mapping analysis of the hydroxyapatite (HAp) samples, oxygen ( a ), phosphorus ( b ), calcium ( c ). ( a ), phosphorus ( b ), calcium ( c ). ( a ), phosphorus ( b ), calcium ( c ). ( a ), phosphorus ( b ), calcium ( c ).