Crystallization process of amorphous silicate with the solar composition: Distribution of Fe / Mg between the olivine and the amorphous silicate

Abstract

According to infrared astronomical observation, the silicates of circumstellar dust are an amorphous material and a crystal of olivine and pyroxene while the silicate of interstellar dust is amorphous material. And the crystal hardly contains iron. We synthesized an amorphous silicate with the solar composition by the sol-gel method, and did the heating experiments. Each sample was analyzed by Infrared absorption spectroscopy and X-ray diffraction. We found that the olivine takes magnesium in preference to iron in the process of crystallization from an amorphous silicate.