Redhammer Günther J, Roth G
Institute of Crystallography, RWTH Aachen, Jägerstrasse 17/19, D-52056 Aachen, Germany.
Acta Crystallogr C. 2004 Apr;60(Pt 4):i33-6. doi: 10.1107/S010827010400321X. Epub 2004 Mar 11.
Unusually large and good-quality single crystals of the synthetic trioctahedral mica KFe(3)(2+)(Al(0.26)Fe(0.76)(3+)Si(3))O(10)(OH)(2) [potassium triiron(II) aluminasilaferrate(III) decaoxide dihydroxide] have been grown hydrothermally. X-ray diffraction data measured at 270 and 100 K have been used to refine the crystal structure, including the positions of the H atoms. This synthetic mica is similar to annite, KFe(3)AlSi(3)O(10)(OH)(2), and crystallizes with the same monoclinic C2/m symmetry. No phase transition has been observed down to 100 K. At low temperature, the ditrigonal distortion of the mica structure increases markedly, while the octahedral and tetrahedral bond lengths tend to decrease and increase, respectively. A detailed comparison of structural parameters in various Fe-rich micas is presented.
通过水热法生长出了异常大且质量优良的合成三八面体云母KFe(3)(2+)(Al(0.26)Fe(0.76)(3+)Si(3))O(10)(OH)(2) [三铁(II)铝硅酸铁(III)十氧化物二氢氧化物钾]单晶。在270 K和100 K下测量的X射线衍射数据已用于精修晶体结构，包括H原子的位置。这种合成云母类似于铁云母KFe(3)AlSi(3)O(10)(OH)(2)，并以相同的单斜C2/m对称性结晶。在低至100 K时未观察到相变。在低温下，云母结构的双三角畸变显著增加，而八面体和四面体键长分别趋于减小和增加。给出了各种富铁云母结构参数的详细比较。
