Nanoscale intergrowths in the bastnäsite–synchysite series record transition toward thermodynamic equilibrium
Nanoscale intergrowths in the bastnäsite–synchysite series record transition toward thermodynamic equilibrium
复制标题
氟碳碳铈矿-合质岩系列中的纳米级共生体记录了向热力学平衡的转变
DOI：
10.1557/s43577-022-00318-1
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发表时间：
2022
期刊：
影响因子：
5
通讯作者：
W. Liu
中科院分区：
文献类型：
--
作者：
C. Ciobanu;N. Cook;A. Slattery;K. Ehrig;W. Liu
向绿色能源技术过渡的步伐加快，导致对稀土元素(REE)的需求增加。[REE(CO3)F]-[Caree(CO3)2F]群中的氟碳酸盐资源丰富，是南澳大利亚州>；100亿吨奥林匹克大坝铜-铀-金-银矿床的主要稀土矿物。在纳米到微米的尺度上，BASTNäSITE和SYNCHYSITE板条的相互生长是规则，而不是例外，并解释了两个端元之间的结构和成分变化。本文对奥林匹克大坝稀土氟碳酸盐矿物学进行了综述，着重阐述了辉石和同辉石间的共生对实现热力学平衡的重要意义。通过高角度环形暗场扫描电子显微镜(HAADF STEM)成像，可以可视化稀土氟碳酸盐的原子尺度周期性和结构模块，进而确定结构域组成，否则低于微束方法的空间分辨率。尽管高度不规则，但这种具有原子尺度相互生长的结构域可以接近每个主体中下一个中间成员相的组成，这意味着在接近热力学平衡的系统中形成。
The accelerated pace of transition to green energy technologies has led to increased demand for rare-earth elements (REEs). Fluorocarbonates from the bastnäsite [REE(CO3)F]—synchysite [CaREE(CO3)2F] group are abundant in nature and the dominant REE minerals in the >10 billion ton Olympic Dam Cu–U–Au–Ag deposit, South Australia. Intergrowths of bastnäsite and synchysite slabs at the nanometer to micron scales are the rule rather than the exception and account for structural and compositional changes between the two endmembers. This article reviews REE-fluorocarbonate mineralogy at Olympic Dam with emphasis on the significance of intergrowths among bastnäsite and synchysite for achievement of thermodynamic equilibrium. Imaging by high-angle annular dark-field scanning transmission electron microscopy (HAADF STEM) allows visualization of atomic-scale periodicity and structural modularity in REE fluorocarbonates and, in turn, determination of domain compositions, which are otherwise below the spatial resolution of microbeam methods. Despite highly irregular, such domains featuring atomic-scale intergrowths can approach the compositions of the next intermediate member phase within each host, implying formation in a system close to thermodynamic equilibrium.
影响因子：
4.8
作者：
S. Al-Ali;F. Wall;R. Fitzpatrick;S. Broom-Fendley;G. Rollinson;A. Brady;J. Pickles;Adam Williams-Ada
通讯作者：
S. Al-Ali;F. Wall;R. Fitzpatrick;S. Broom-Fendley;G. Rollinson;A. Brady;J. Pickles;Adam Williams-Ada