Abstract
Various members in the chrysotile-pecoraite solid solutions were obtained by hydrothermal synthesis under the conditions of 350°C, 500kg/cm2 (water vapour pressure) and 10 days. The products were examined by X-ray diffraction technique, IR spectroscopy, thermal analysis, electron microscopy and heat treatment. The main results obtained are summarized below.
(1) All products had homogeneous distribution of magnesium and nickel in the octahedral sheet.
(2) In the IR spectra the frequencies of four bands related to hydroxyl group (3695, 3660, 402 and 300 cm-1 for the magnesium end member) varied linearly with increasing nickel content to 3646, 3618, 374 and 317 cm-1 for the nickel end member.
(3) Dehydroxylation temperature of the member with higher nickel content was lower than that of the member with higher magnesium content.
(4) After heating the long spacing phase was observed in the members with higher nickel content. This phase was characterized by the broad reflection of 12-14Å, and seemed to preserve the original layer structure of serpentine.
(5) In the nickel end member some hydroxyls remained even at high temperature of 900°C.
