Topological synthesis of Mg-based silicate nanosheet bundles from CaSi₂ crystal powders

Abstract

Mg-based silicate nanosheet bundles were synthesized by thermal annealing using CaSi 2 crystal powders and MgCl 2 with the appropriate O 2 and/ or H 2 O content in the atmosphere. The silicate compound nanosheet bundle formation was caused by the nanosheet bundle synthesis by Ca-atom extraction from the CaSi 2 crystal powders followed by Mg incorporation along with the oxidation and/or hydroxidation by employing the topological synthesis technique. The morphological and structural properties of the Mg 2 SiO 4 nanosheet bundles were clarified and the growth mechanism of the silicate nanosheets was discussed. The growth feature of the Mg-silicates and related materials, such as Mg 2 Si, MgO, SiO 2 and magnesium silicate hydroxides, is discussed from thermodynamic points of view. The possible formation of magnesium silicate hydroxides as a flake-like structure is also mentioned.

Fine structural and photoluminescence properties of Mg2Si nanosheet bundles rooted on Si substrates

“…It should be mentioned that PL emissions from Mg 2 SiO 4 are possible as the oxygen distribution indicates the existence of Mg-silicate phases. 51) According to the literature, a series of 1.9-2.3 eV emission peaks from Mg 2 SiO 4 have been observed. 52) Considering that the equivalent of peak P3 was not observed in the VIS spectra under 405 nm excitation, the P3 peak is likely not due to Mg 2 SiO 4 .…”

Synthesis, structural and luminescence properties of MgO, Mg₂SiO₄ and MgO/Mg₂SiO₄ nanostructures

“…Mg 2 SiO 4 nanosheet bundles were synthesized at 600 °C for 10 h using a previously described technique. 9) The CaSi 2 and MgCl 2 mixed powders in a molar ratio of MgCl 2 :CaSi 2 = 10:1 were placed in a container inside a sealed stainless-steel cell under an Ar atmosphere with 3.7 % oxygen. MgO/Mg 2 SiO 4 nanostructures were synthesized by extracting Ca atoms from CaSi 2 powder via thermal treatment with MgCl 2 .…”

“…The synthesis technique, conditions, structural and morphological properties, and growth mechanism of Mg 2 SiO 4 have been already described elsewhere. 9) The growth mechanism mainly involves Ca-atom extraction from the CaSi 2 powders followed by Mg incorporation along with the oxidation and/or hydroxidation. 9) In the bundles, some amount of Si remains in the Mg 2 SiO 4 nanostructures.…”

“…The synthesis of Mg 2 SiO 4 nanosheet bundles and its structural properties have been reported previously. 9) In this study, a simple method for the synthesis of MgO nanosheet structures was developed, and the CL and PL properties of the MgO and MgO/Mg 2 SiO 4 nanostructures were investigated.…”

Synthesis of Mg2Si1−X Ge X solid-solution nanostructures by thermal annealing of CaSi2 crystal powders with Ge and MgCl2/Mg

“…4,5) In addition, several stoichiometric compounds, such as Mg 2 Si, MnSi 1.7 , Mg 2 SiO 4 nanosheet bundles, and CaF 2 nanostructures were synthesized. [6][7][8][9] Furthermore, the crystalline solid-solutions enable variations in stoichiometry of the continuum, which correspond to the variations in structural and physicochemical properties, and offer an opportunity to produce and finely tune the desired properties.…”