X-ray and HRTEM study of sursassite: Crystal structure, stacking disorder, and sursassite-pumpellyite intergrowth
X-ray and HRTEM study of sursassite: Crystal structure, stacking disorder, and sursassite-pumpellyite intergrowth
复制标题
钠铝锰矿的 X 射线和 HRTEM 研究：晶体结构、堆积无序以及钠铝锰矿-斜方铅矿共生
DOI：
10.1007/bf00309643
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发表时间：
1984
影响因子：
1.4
通讯作者：
M. Pasero
中科院分区：
文献类型：
--
作者：
M. Mellini;S. Merlino;M. Pasero
钠辉石为单斜晶系，空间群为P21/m，a=8.70，b=5.79，c=9.78ä，β=108.9°。用X射线衍射仪测定了其晶体结构，精化Tor=0.065，得到了理想的晶体化学式：Mn2Al3[(OH)3(SiO4)(Si2O7)]。闪锌矿与纤锌矿Ca2Mn3[(OH)3(SiO4)(Si2O7)]同构，与纤锌矿Ca2Al3[(OH)3(SiO4)(Si2O7)]关系密切。事实上，除了不同的化学成分外，闪锌矿和闪锌矿都是由共同的结构层组成的，这些结构层由不同的堆积矢量重复。高分辨电子显微镜(HRTEM)分析表明，常见的(001)晶片与较厚的(001)闪锌矿晶片相互生长。通常客体晶片沿[001]方向有几个单位晶胞厚，沿(001)晶面连续，但也有少见的间断晶片。
Sursassite is monoclinic, space groupP21/m, a=8.70,b=5.79,c=9.78 Å, β=108.9°. The crystal structure was determined with X-rays and refined toR=0.065, obtaining Mn2Al3[(OH)3(SiO4)(Si2O7)] as ideal crystal chemical formula. Sursassite, isostructural with macfallite Ca2Mn3[(OH)3(SiO4)(Si2O7)], is closely related to pumpellyite Ca2Al3[(OH)3(SiO4)(Si2O7)]. In fact both sursassite and pumpellyite, apart from the different chemical composition, are built up by common structural layers, which are repeated by different stacking vectors. As a result, faulted stacking sequences are energetically possible.Examination byhigh resolution transmission electron microscopy(HRTEM) shows that frequent (001) pumpellyite-like lamellae are intergrown with thicker (001) sursassite lamellae. Usually, the guest lamellae are a few unit cells thick along [001] and continuous along the (001) plane, although also rare interrupted lamellae are found.