Tailoring Hydroxyapatite via Mg and Zn Co-Doping A Crystallographic Engineering Approach
Sabrina Ocha Felinda (a*), Fainan Failamani, Irma Mulyani (a)

(a, b, c) Division of Inorganic and Physical Chemistry, Institut Teknologi Bandung, Jl. Ganesha no. 10, Bandung, 40132, Indonesia.

Abstract

Hydroxyapatite is a calcium phosphate biomaterial whose crystal structure and composition resemble the mineral phase of bone. Its properties are strongly influenced by crystallinity, lattice distortion, and phase stability. Thermal treatment can improve structural ordering, but often causes crystal growth and partial transformation to other calcium phosphate phases. Therefore, structural control is required to maintain phase purity and stability. In this work, pure hydroxyapatite as well as magnesium doped, zinc doped, and magnesium zinc codoped hydroxyapatite were synthesized by wet precipitation using calcium and phosphate precursors with a calcium to phosphorus ratio of 1.67. Dopant ions were introduced during nucleation to ensure homogeneous incorporation. The powders were washed, dried, and calcined at temperatures between 700 and 800 C. X ray diffraction confirmed single phase hexagonal hydroxyapatite under optimized conditions. Dopant substitution produced lattice contraction, reduced crystallite size, and modified crystallinity. Magnesium inhibited crystal growth, zinc introduced lattice disorder, and codoping generated a synergistic effect that stabilized the structure and suppressed coarsening. This approach enables controlled structural tuning of hydroxyapatite for bone regeneration applications.

Keywords: Hydroxyapatite, Mg Zn co-doping, Lattice distortion, Bone regeneration.

Topic: Inorganics Chemistry