Low‐Temperature Crystallization of Forsterite and Orthoenstatite

Abstract

MgO-SiO 2 precursor gels were prepared by mixing tetramethoxysilane (TMOS) or tetraethoxysilane (TEOS), H 2 O, and magnesium metal in methanol. Forsterite (Mg 2 SiO 4 ) and orthoenstatite (MgSiO 3 ) were crystallized from their precursors at temperatures as low as 500°and 700°C, respectively. The chemical compositions of the crystallized phases were richer in MgO content than those of the starting materials. Inductively coupled plasma analysis showed that an amorphous SiO 2 -rich phase was present, together with crystalline phases. We speculate that the amorphous SiO 2 -rich phase has an important role in the lowtemperature crystallizations of these magnesium silicates. Characterization of the preparation process via liquid-state 29 Si nuclear magnetic resonance (NMR) indicated that the breakage of the ≡Si−O−Si≡ bond was caused by the addition of magnesium metal. Solid-state 29 Si NMR showed that the Mg−O−Si bond might form in as-prepared specimens.

Synthesis of a forsterite powder by combined ball milling and thermal treatment

“…It belongs to the group of olivine. Like clinoenstatite, with the formula MgSiO 3 , forsterite has an extremely low electrical conductivity [1]. This makes forsterite ceramics an ideal substrate material for electronics.…”

“…Forsterite has been synthesized by solid state reaction of MgO and SiO 2 [5] or bauxite and MgCO 3 [6], and by various sol-gel methods [1,7,8] which include a H 2 O 2 assisted process [9].…”

Characterization of Nanocrystalline Forsterite Fiber Synthesized via the Sol–Gel Process

“…Forsterite is known to be an insulator at high frequencies; its precursor powder and xerogel have been synthesized via the sol-gel method. [7][8][9][10] A previous systematic study 11 has shown that acetate anion behaves as a ligand and modifies the molecular structure of the gel, playing an important role in the formation of spinnability when the forsterite precursor solution is hydrolyzed with an adequate amount of acetic acid. Factors affecting the properties or type of the hydrolyzed molecular structure have been investigated.…”

Ceramic compositions based on nano forsterite/nano magnesium aluminate spinel powders

“…It belongs to the group of olivine. Like clinoenstatite, with the formula MgSiO 3 , forsterite has an extremely low electrical conductivity [4]. This makes forsterite ceramics an ideal substrate material for electronics.…”