Figure 7. The 3D images of elemental mapping analysis of the 20ZnHAp samples. oxygen ( a ), Figure 7. The 3D images of elemental mapping analysis of the 20ZnHAp samples. oxygen ( a ), Figure 7. The 3D images of elemental mapping analysis of the 20ZnHAp samples. oxygen ( a ), Figure 7. The 3D images of elemental mapping analysis of the 20ZnHAp samples. oxygen ( a ), phosphorus ( b ), calcium ( c ) and zinc ( d ) ZnHAp: zinc-doped hydroxyapatite . phosphorus ( b ), calcium ( c ) and zinc ( d ) ZnHAp: zinc-doped phosphorus ( b ), calcium ( c ) and zinc ( d ) ZnHAp: zinc-doped hydroxyapatite . phosphorus ( b ), calcium ( c ) and zinc ( d ) ZnHAp: zinc-doped hydroxyapatite .