The defect aggregation of RE3+ (RE = Y, La similar to Lu) in MF2 (M = Ca, Sr, Ba) fluorites
The defect aggregation of RE3+ (RE = Y, La similar to Lu) in MF2 (M = Ca, Sr, Ba) fluorites
复制标题
RE3 (RE = Y, La ~ Lu) 在 MF2 (M = Ca, Sr, Ba) 萤石中的缺陷聚集
DOI：
10.1016/j.materresbull.2020.110788
复制
发表时间：
2020
影响因子：
5.4
通讯作者：
Liang Hongbin
中科院分区：
文献类型：
--
作者：
Ma Fengkai;Su Fang;Zhou Rongfu;Ou Yiyi;Xie Liujing;Liu Chunmeng;Jiang Dapeng;Zhang Zhen;Wu Qinghui;Su Liangbi;Liang Hongbin
将三价镧系掺杂萤石的聚类分为四个阶段。本文采用基于第一性原理的密度泛函理论（DFT）计算方法研究了前三级离散簇的特征。结果表明，第一阶段ec4和c3v的相对稳定性与第二和第三阶段集群的相对稳定性密切相关。在最近位置具有间隙Fi−的更稳定的lec4v可以稳定第二个立方子晶格中心，而在次近位置具有间隙Fi−的c3v可以稳定第三个方形反棱镜团簇。晶格失配和投影态密度（pDOS）结果表明，Fi−、RE3+和周围晶格阴离子之间的静电、应变、成键和杂化耦合控制了位点占用和相关性。这些簇和簇特征可以被调制，并用于调整上下转换的光致发光，用于设计新的镧系掺杂萤石材料。
The clustering of trivalent lanthanide-doped fluorite was divided into four stages. Characters of the first three stage discrete clusters were studied by the density functional theory (DFT) based first principles calculation in the work. The results revealed the relative stabilities of first stageC4vandC3vwere intimately correlated with that of the second and third stage clusters. The more stableC4vwith interstitial Fi−at the nearest site would stabilize the second cubic sublattice centers andC3vwith Fi−at next nearest site for the third square antiprism clusters. The lattice mismatch and projected density of states (pDOS) results indicated that coupling of electrostatic, strain, bonding and hybridization among Fi−, RE3+and surrounded lattice anions controlled the site occupation and the correlations. The clusters and clustering features could be modulated and utilized to tune up- and down-conversion photoluminescence for designing of new lanthanide-doped fluorite materials.