Laser-Induced Synthesis of Crystalline Silicon Compounds from Aluminum–Silica–Carbon Powder

The paper investigates the feasibility of laser-induced synthesis of crystalline silicon compounds from a powder system consisting of metallic aluminum, amorphous silica, and carbon atoms. Using pulsed laser radiation (wavelength 1064 nm), it is experimentally demonstrated that varying the processing parameters—pulse energy, repetition rate, scanning speed, and pulse duration—allows for targeted control of the phase composition of the products. Modes for the selective formation of crystalline silicon, mullite, and intermediate acid-soluble aluminosilicates are established. Using a simplified thermal model, a correlation is demonstrated between the achieved temperature in the irradiation zone and the formation of specific phases, with not only the peak temperature at the laser point but also the exposure time playing a key role. It is shown that crystalline acid-soluble silicate phases preceded the formation of mullite. The results of low-temperature laser synthesis of crystalline silicon-containing materials hold great promise for various applications.