Fabrication and Characterization of Short Silicon Nitride Fibers from Direct Nitridation of Ferrosilicon in N2 Atmosphere

Abstract

Short silicon nitride fibers were fabricated by direct nitridation of ferrosilicon in N2 atmosphere, and their structure and possible growth mechanism were characterized and investigated. The rod-like fibers which were α-Si3N4 with a low degree of crystallization and a high aspect ratio had a diameter of about 4 μm and a length close to a few millimeters. Belt-like fibers with a width about 5 μm and a thickness about 1 μm were also found in the nitrides. Scanning electron microscope (SEM), transmission electron microscope (TEM), high resolution transmission electron microscope (HRTEM), and selected area electron diffraction (SAED) investigations indicated that the fibers were single-crystalline α-Si3N4 with few amorphous distributed in the edge region, and the fibers grew by vapor–liquid–solid (VLS) mechanism.

Modeling of Non-Ferrous Metallurgy Waste Disposal with the Production of Iron Silicides and Zinc Distillation

“…Simultaneously with this simulation, the conversion of iron (10.6–99.996%) and silicon (10.7–69.44%) into an alloy with the possibility of forming iron silicide compounds with a predicted Si content within 18–28% (which, according to GOST 1415-93 (ISO 5445-80), can be identified as ferrosilicon grades FS18, FS20 and FS25) under optimum conditions (1900–2000 K) of the studied temperature regime. The obtained results of the study of the disposal of clinker waste in order to reduce the anthropogenic impact on the biosphere of the region with the possibility of obtaining ferroalloy and zinc sublimates are new and can complement the ongoing research in this direction [ 8 , 24 , 25 , 26 , 27 , 28 , 39 , 71 , 72 , 73 , 74 , 75 , 76 ].…”

“…Industrial waste located in dumps and containing in its chemical composition heavy non-ferrous metals and various compounds of silicon, calcium, aluminum and iron has a negative impact on the environment from the point of view of ecology, in particular on public health, flora and fauna [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. However, based on its chemical composition, it is valuable and can serve as a secondary technogenic raw material for various kinds of industries, for example in the metallurgical, construction, chemical and other industries [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 …”

“…However, based on its chemical composition, it is valuable and can serve as a secondary technogenic raw material for various kinds of industries, for example in the metallurgical, construction, chemical and other industries [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 ]. Thus, in Kazakhstan, in the process of extracting non-ferrous metals at a number of plants, since the 1920s and up to the present, in a number of areas, in particular, in the east Kazakhstan and Turkestan regions, there is a significant amount of clinker waste from the cultivation of various raw materials, which is now stored in dumps, occupying fertile lands and polluting the soil, surface and groundwater, the atmosphere, penetrating animal and human organisms through the migration of heavy metals along the food chain [ 9 ,…”

Effect of Tb3+ and Ce3+ co-doping on the structural stability and photoluminescence properties of hexagonal boron nitride phosphors

“…Wang reports on a green phosphor, SrLuSi 4 N 7 :Ce 3+ , Tb 3+ , capable of tuning its color under ultraviolet excitation for use in white LEDs [17]. Binary nitrides, known for their straightforward structure and wide bandgap, have gained attention as matrices for nitride phosphors, including rare earth ion-doped GaN, AlN, and Si 3 N 4 phosphors [18][19][20][21][22][23][24]. Hexagonal boron nitride (h-BN) possesses a wide bandgap of approximately 5.2 eV and outstanding thermochemical stability, and has been identi ed as an ideal host material for inorganic phosphors [25][26][27][28].…”

Atomistic Construction of Silicon Nitride Ceramic Fiber Molecular Model and Investigation of Its Mechanical Properties Based on Molecular Dynamics Simulations

“…The smart minimizer method is then employed for structural optimization of the periodic cell system, and the cell with the lowest energy configuration is selected. The initial optimization temperature for the amorphous periodic cells is set to 300 K, with a density of 0.8 g/cm 3 . The specific range of initial temperature (300-800 K) is chosen based on the actual solidification reaction temperature for favorable molecular motion and reasonable model construction.…”