Catalytic Effects of Cr on Nitridation of Silicon and Formation of One-dimensional Silicon Nitride Nanostructure

Abstract

The catalytic effects of chromium (Cr) on the direct nitridation of silicon (Si) and morphology of nitridation product were investigated. Cr dramatically improved the conversation of Si to silicon nitride (Si3N4). The complete conversion was achieved at 1350 °C upon addition of 1.25 wt% Cr. This temperature was much lower than that required in the case without using a catalyst. Meanwhile, Cr played an important role in the in-situ growth of one-dimensional (1-D) α-Si3N4 nanostructures. α-Si3N4 nanowires and nanobelts became the primary product phases when 5 wt% Cr was used as the catalyst. The growth processes of the 1-D α-Si3N4 nanostructures were governed by the vapor-solid mechanism. First-principle calculations suggest that electrons can be transferred from Cr atoms to N atoms, facilitating the Si nitridation.

Preparation and enhanced adsorption properties for CO2 and dyes of amino‐decorated hierarchical porous BCN aerogels

“…The electronic changes were characterized by the Mulliken population analysis. The absorption energy between CO 2 molecule and BCN was obtained by the following Equation 22 :where E ad is the adsorption energies, is the electronic energies of the CO 2 molecule, E BCN is the electronic energies of the BCN model, and is the total electronic energies of the system of CO 2 adsorbed on BCN.…”

“…The electronic changes were characterized by the Mulliken population analysis. The absorption energy between CO 2 molecule and BCN was obtained by the following Equation 22 :…”

Effect of Y2O3additive on nitridation of diamond wire silicon cutting waste

“…The third stage is the nitriding process of DWSCW. A significant endothermic peak appears at this stage, which is caused by the melting of silicon in cutting waste 30 . In addition, the sample with 8 wt% Y 2 O 3 additive has two sharp exothermic peaks at 1300 and 1400°C, respectively.…”

“…A significant endothermic peak appears at this stage, which is caused by the melting of silicon in cutting waste. 30 In addition, the sample with 8 wt% Y 2 O 3 additive has two sharp exothermic peaks at 1300 and 1400 • C, respectively. This indicates that at 1300 • C, Y 2 O 3 additive begins to be involved in nitriding; at 1400 • C, a large amount of nitriding begins, and the nitriding reaction of samples with 8 wt% Y 2 O 3 is more stronger than that of samples without additive.…”

Function mechanism of Y2O3 additive in silicon powder nitridation

“…Meanwhile, other researchers have also shown the same nitridation behavior of silicon . Therefore, several kinds of metal additives such as Fe, Cr and so on are introduced in silicon powder to modify the nitriding process so as to reduce the nitriding time. It is well known that Fe and Cr can enhance the nitridation of silicon and the formation of β‐Si 3 N 4 by forming the low melting phases FeSi x and Cr x Si y .…”