Department of Materials Science and Engineering, Kyoto University, Kyoto 606-8501, Japan.
J Phys Condens Matter. 2010 Sep 29;22(38):384213. doi: 10.1088/0953-8984/22/38/384213. Epub 2010 Sep 7.
The local environment of substitutional Zn(2+) in Ca-deficient hydroxyapatite (HAp) was investigated using experimental and theoretical analyses of the x-ray absorption near edge structure (XANES). For Zn-K XANES calculations, two situations of Zn(2+) were considered. One was Zn(2+) substituted for Ca sites in perfect HAp, and the other was a Ca-deficient HAp model of substitutional Zn(2+) associated with a Ca(2+) vacancy charge compensated by two protons. The model of Zn(2+) in perfect HAp did not reproduce the experimental Zn-K XANES spectrum. In contrast, the Ca-deficient HAp model agreed well with the experimental spectrum. This indicates that substitutional Zn(2+) in Ca-deficient HAp is associated with the Ca(2+) vacancy complex in HAp.
采用实验和理论分析的方法，研究了取代钙的羟基磷灰石（HAp）中锌（Zn）的局部环境。对于 Zn-K XANES 计算，考虑了两种 Zn（2+）情况。一种是 Zn（2+）取代完整 HAp 中的 Ca 位，另一种是与一个 Ca（2+）空位相关的取代 Zn（2+）的 Ca 缺乏 HAp 模型，该空位的电荷由两个质子补偿。Zn（2+）在完整 HAp 中的模型不能重现实验 Zn-K XANES 谱。相比之下，Ca 缺乏 HAp 模型与实验谱吻合较好。这表明 Ca 缺乏 HAp 中的取代 Zn（2+）与 HAp 中的 Ca（2+）空位复合物有关。
