Dehydration of the zeolite merlinoite from the Khibiny massif, Russia: an in situ temperature-dependent single-crystal X-ray study

作者：Pakhomova Anna S^*; Armbruster Thomas; Krivovichev Sergey V; Yakovenchuk Victor N

来源：European Journal of Mineralogy, 2014, 26(3): 371-380.

DOI：10.1127/0935-1221/2014/0026-2380

• merlinoite
• zeolite
• dehydration
• crystal structure
• high temperature

Dehydration behaviour of the zeolite merlinoite, NaK11[Al12Si20O64]center dot 15H(2)O, from the Khibiny massif (Russia) was studied by means of single-crystal X-ray diffraction conjoined with step-wise heating to 225 degrees C. At room temperature merlinoite has the space group Immm with a = 14.0312(5), b = 14.2675(6), c = 10.0874(4) angstrom, and V = 2019.40(14) angstrom(3). At 75 degrees C the merlinoite structure undergoes pronounced dehydration accompanied by a phase transition to a structure that has the space group P4(2)/nmc and remains consistent at elevated temperature. A fully dehydrated phase occurs at 200 degrees C (at 225 degrees C: a = 13.341(4), b = 13.341(4), c = 9.707(4) angstrom, V = 1727.7(12) angstrom(3)). Dehydration-induced framework distortion and symmetry were found to be different from those observed for synthetic potassium merlinoite with the K-11.5[Al11.5Si20.5O64]center dot 15H(2)O composition.

• 出版日期2014-6