In this paper, experimental method and first-principles calculations were combined to study the properties of pure hydroxyapatite and Zn-doped hydroxyapatite. Pure and Zn-doped hydroxyapatite (HA) powders were synthesized using the hydrothermal method. The FTIR spectra show that the adding of Zn atoms makes the intensity of PO₄³⁻ stretching peaks become weaken and obscure. In addition, the O-H bending peaks at 3570 and 632 cm⁻¹ become weaker and broader. The XRD patterns show that the replacement of Zn ion in the HA structure leads to the distortion in HA lattice, which is shown and proved by the TEM analysis. First-principles calculations based on density functional theory (DFT) method were applied to investigate the Zn-doped hydroxyapatite. The elastic properties of HA, HA with Ca²⁺(II) vacancy, and Zn doped HA systems were calculated. Through the calculation, we found that the doping of Zn atoms made the elastic modulus of HA crystal becoming soft. The elastic properties dropped dramatically when there is a vacancy in the Ca²⁺(II) position. Compared with the HA-VCa²⁺ structure, the Zn-doped HA has better elastic properties and stability. The local structure of the substitution position was presented and analyzed. In the Zn-doped HA structure, the OH⁻ group adjacent to Zn²⁺ is significantly displaced from the c axis toward to the Zn²⁺, making the lattice distorted. The distortion of the crystal lattice is responsible for the weakness of the P-O stretching peaks and O-H bending peaks in the FTIR spectra of the Zn doped HA crystal. The softness of the elastic modulus is also caused by the distortion of the lattice and the weak bonding force between Zn atom and O atom.

本文结合实验方法和第一性原理计算研究了纯羟基磷灰石和锌掺杂羟基磷灰石的性能。使用水热法合成了纯锌粉和掺锌羟基磷灰石（HA）粉末。FTIR光谱表明，添加Zn原子会使PO ₄ ^3-拉伸峰的强度减弱和模糊。另外，OH弯曲峰在3570和632cm ^-1处变得越来越弱。XRD图谱表明，HA结构中Zn离子的置换导致HA晶格畸变，这是通过TEM分析证实的。基于密度泛函理论（DFT）方法的第一性原理计算被用于研究Zn掺杂的羟基磷灰石。计算了HA的弹性特性，具有Ca ²⁺（II）空位的HA和Zn掺杂的HA体系。通过计算，我们发现Zn原子的掺杂使HA晶体的弹性模量变软。当Ca ²⁺（II）位置存在空位时，弹性性能急剧下降。与HA-VCa ²⁺相比在结构上，Zn掺杂的HA具有更好的弹性和稳定性。介绍并分析了替代位置的局部结构。在掺杂Zn的HA结构中，OH ^-相邻的Zn组²⁺被显著从移位Ç朝向所述轴线的Zn ²⁺，使得扭曲晶格。晶格的变形是造成掺杂锌的HA晶体的FTIR光谱中PO拉伸峰和OH弯曲峰弱的原因。弹性模量的柔软性还由晶格的变形和Zn原子与O原子之间的弱结合力引起。