Sol-gel Synthesis and Crystallization of Magnesium and Calcium Rich Silicate

Introduction: Magnesium rich amorphous silicates are major component of dust in the interstellar medium. At the birth of stars, when the ISM cloud collapses, dusts are incorporated in the forming disk. Temperature progressively increases along the disk when approaching the inner regions [1,2,3]. So they were subjected to various temperature conditions for long periods as they travel along the disk by radial transport [4,5]. Because they are processed by irradiation [6] in the ISM cloud, silicate dusts are far from equilibrium in addition to their small size and their porosity. Structural features of precursors (irradiated, nanostructured, likely porous aggregates) may influence their crystallization behavior under thermal annealing. Understanding how such disordered materials behave during their crystallization could probably give insights into formation of minerals studied in infrared observatories or found in natural object (IDPs, fine-grained micrometeorites, finegrained matrix of primitive chondrites, Wild 2 dust).