First-principles calculations of divalent substitution of Ca2+ in tricalcium phosphates
First-principles calculations of divalent substitution of Ca2+ in tricalcium phosphates
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DOI：
10.1016/j.actbio.2015.05.014
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发表时间：
2015-09-01
影响因子：
9.7
通讯作者：
Nakamura, Atsutomo
中科院分区：
文献类型：
--
作者：
Matsunaga, Katsuyuki;Kubota, Tomonori;Nakamura, Atsutomo
采用第一性原理计算方法研究了Mg 2+、Zn 2+、Sr 2+和Ba 2+在磷酸三钙（TCP）中的局域原子排列和热力学稳定性.存在α-TCP和β-TCP的两种变体，并且在晶体结构中存在许多不等价的Ca位点。结果发现，每个二价阳离子具有能量优先的Ca取代位点。Mg ~（2+）和Zn ~（2+）有利于β-TCP中Ca ~（-5）位的取代，而Sr ~（2+）和Ba ~（2+）则有利于β-TCP中Ca ~（-3）和Ca ~（-4）位的取代。这些阳离子的计算的网站偏好是在合理的协议与现有的实验数据。此外，发现这些阳离子在特定的Ca位点具有负形成能，特别是在β-TCP中，表明β相的稳定化。(C)2015 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
First-principles calculations were carried out to reveal local atomic arrangements and thermodynamic stability of substitutional divalent cations of Mg2+, Zn2+, Sr2+ and Ba2+ in tricalcium phosphates (TCPs). There are two modifications of alpha-TCP and beta-TCP, and a number of inequivalent Ca sites are present in the crystal structures. It was found that each divalent cation has energetically preferential Ca sites for substitution. For instance, Mg2+ and Zn2+ favor the substitution at the Ca-5 site of beta-TCP while Sr2+ and Ba2+ tend to occupy Ca-3 and Ca-4 in the beta-type crystal structure. The calculated site preference of these cations was in reasonable agreement with available experimental data. Moreover, it was found that these cations have negative formation energies at specific Ca sites especially in beta-TCP, indicating the stabilization of the beta phase. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.