Hot Corrosion Mechanism of Silicon Nitride Based Ceramics Exposed to Coal Slag Containing Potassium Sulfate

1994 ◽  
Vol 367 ◽  
Author(s):  
Z.B. Yu ◽  
W.H. Li ◽  
N.F. Li
Keyword(s):  
Silicon Nitride ◽  
Silicon Dioxide ◽  
Potassium Salt ◽  
Potassium Sulfate ◽  
Silicate Melt ◽  
Corrosion Mechanism ◽  
Silica Layer ◽  
Before And After ◽  
Different Temperatures ◽  
Coal Slag

AbstractThe corrosion of three kinds of silicon nitride based ceramics by static liquid potassium sulfate-coal slag immersion was investigated at high temperatures. The reaction kinetics between silicon nitride based ceramics and coal-slag-potassium sulfate was investigated, different kinetic curves were obtained at different temperatures, it was l-(l-a)1/3=kt at 1350°C and a=kt2at 1400°C. Phase composition, microstructure of the materials before and after corrosion were studied by XRD, SEM/EDAX, and EPMA etc, which lead to the following detailed corrosion mechanism: (1) oxidation of silicon nitride based ceramics by potassium salt and oxygen in air simultaneously and formation of silicon dioxide. (2) melting of as-formed silica by potassium sulfate or K-contained silicate and resulting in a silicate melt Me-K20-xSiO2, and (3) formation of a protective silica layer below the silicate melt.

scholarly journals Thermal Induced Clustering of Polysilicon Film on Silicon Nitride/Silicon Dioxide Bed on Silicon Substrate

1970 ◽  
Vol 8 (8) ◽  
pp. 10-14
Author(s):  
Shobha Kanta Lamichhane
Keyword(s):  
Grain Size ◽  
Silicon Nitride ◽  
Silicon Dioxide ◽  
Silicon Substrate ◽  
Cluster Formation ◽  
Chemical Vapour ◽  
Contact Mode ◽  
Polysilicon Film ◽  
Pressure Chemical ◽  
Different Temperatures

Polysilicon (PS) grains are clustered in an order in the presence of thermal doping of boron in low pressure chemical vapour deposition (LPCVD). PS layer is lying on Silicon Nitride/Silicon dioxide bed over (100) silicon substrate. The doped PS at different temperatures has been analyzed for the grain size and the shape of the clusters, employing non-contact mode Atomic Force Microscopy (AFM). The grain size of the PS remains intact without a significant change with increasing doping temperature. A substantial increase in the cluster size and its density of the grains has been observed. The cluster formation mechanism induced by thermal variation is discussed in the context of recorded AFM images. The clusters lead to PS rings comprising of grains of the size of 100 nm. Keywords: Doping; Polisilicon; Nanoscale; AFM; MEMS; LPCVD; Contactmode. DOI: 10.3126/sw.v8i8.3839 Scientific World Vol.8(8) 2010 pp.10-14

Surface Characterization of DNA Microarray on Silicon Dioxide and Compatible Silicon Materials in the Immobilization Process

2001 ◽  
Vol 711 ◽  
Author(s):  
Wen Xu ◽  
Jiong Li ◽  
Mei Xue ◽  
Maria Carles ◽  
Dieter Wilhelm Trau ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Silicon Dioxide ◽  
Dna Microarray ◽  
Surface Characterization ◽  
Specific Area ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Covalent Immobilization ◽  
Dna Oligonucleotides ◽  
Before And After

ABSTRACTIn this work, the surface properties of a DNA microarray formed on silicon based solid support are studied at different stages during the hybridization process. A modified immobilization process using the covalent immobilization of thiol-terminated DNA oligonucleotides on self-assembled layers of (3-mercaptopropyl) trimethoxysilane (MPTS) by disulfide bond formation is used to selectively attach DNA probes onto the surface of silicon dioxide. Contact angle measurement is used to monitor the bonding of MPTS on the surface. Atomic force microscopy (AFM) shows an increase in particle size before and after the growth of the MPTS layer. Fluorescence microscopy reveals the success of hybridization of complementary oligonucleotides labeled by FAM to the probe. The effects of modified immobilization process on other common material in silicon processing are also studied. As a result of the corrosive chemical used in the process, common metals used in micro-fabrication processes like aluminum are etched away. Silicon nitride is not affected by the immobilization and hybridization process, and thus can be used as a passivation and isolation material to conform the DNA to a specific area for DNA microarray to reduce cross-talk. The fluorescence image from the scanner indicates silicon nitride can effectively be used as an isolation material with linewidth down to 1 μm.

scholarly journals Dynamic variations in salinity and potassium grade of a potassium-rich brine deposit in Lop Nor basin, China

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lichun Ma ◽  
Kai Wang ◽  
Yu Zhang ◽  
Qingfeng Tang ◽  
Hui Yan
Keyword(s):  
Large Scale ◽  
Sustainable Use ◽  
Potassium Sulfate ◽  
Middle Pleistocene ◽  
Underground Brine ◽  
Average Decrease ◽  
Rational Development ◽  
Mining History ◽  
Before And After ◽  
Lop Nor

AbstractThe Quaternary Lop Nor playa is the largest production base of potassium sulfate in the world. It has a mining history of more than 10 years, and its share in the Chinese potassium sulfate market is about 50% to-date. In this basin, the high-salinity potassium-rich brines are mainly contained in Middle Pleistocene–Holocene glauberite strata. Based on the monitoring of the underground brine table and geochemical analysis, this study reveals variations in the underground brine table and potassium-bearing grade before and after large-scale mining in the Lop Nor potash deposit. The results showed that the underground brine table and potassium sulfate grade decreased by varying degrees over sub-mineral areas after large-scale mining. The underground brine table declined by 8.5 m, on average, in the Luobei depression, by 6.4 m in the Tenglong platform and by 1.9 m in the Xinqing platform. However, the potassium-bearing grade showed the different trend. The Tenglong platform had the largest decline with average decreases in layers W1, W2 and W3 of 18.2%, 13.0% and 24.8%, respectively. In the Xinqing platform, the average decrease in layersW2 and W3 were 17.4% and 16.0% respectively. The Luobei depression decreases were relatively small (W1, W2 and W3 decreased 4.3%, 4.2% and 3.1%, respectively). This research provides a theoretical basis for the rational development and sustainable use of the potassium-rich brines in the Lop Nor basin.

scholarly journals Research on Sapphire Deep Cavity Corrosion and Mask Selection Technology

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 136
Author(s):  
Yiingqi Shang ◽  
Hongquan Zhang ◽  
Yan Zhang
Keyword(s):  
Silicon Nitride ◽  
Silicon Dioxide ◽  
Chemical Vapor ◽  
Nitride Layer ◽  
Wet Etching ◽  
Silicon Dioxide Layer ◽  
Etching Depth ◽  
Deep Cavity ◽  
Mask Layer ◽  
Layer Composite

Aimed at the problem of the small wet etching depth in sapphire microstructure processing technology, a multilayer composite mask layer is proposed. The thickness of the mask layer is studied, combined with the corrosion rate of different materials on sapphire in the sapphire etching solution, different mask layers are selected for the corrosion test on the sapphire sheet, and then the corrosion experiment is carried out. The results show that at 250 °C, the choice is relatively high when PECVD (Plasma Enhanced Chemical Vapor Deposition) is used to make a double-layer composite film of silicon dioxide and silicon nitride. When the temperature rises to 300 °C, the selection ratio of the silicon dioxide layer grown by PECVD is much greater than that of the silicon nitride layer. Therefore, under high temperature conditions, a certain thickness of silicon dioxide can be used as a mask layer for deep cavity corrosion.

scholarly journals Experimental Investigation of Wave Velocity-Permeability Model for Granite Subjected to Different Temperature Processing

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Guanghui Jiang ◽  
Jianping Zuo ◽  
Teng Ma ◽  
Xu Wei
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Wave Velocity ◽  
Pore Fluid ◽  
Rock Matrix ◽  
Permeability Model ◽  
Wave Velocities ◽  
Before And After ◽  
Different Temperatures ◽  
Increasing Temperature

Understanding the change of permeability of rocks before and after heating is of great significance for exploitation of hydrocarbon resources and disposal of nuclear waste. The rock permeability under high temperature cannot be measured with most of the existing methods. In this paper, quality, wave velocity, and permeability of granite specimen from Maluanshan tunnel are measured after high temperature processing. Quality and wave velocity of granite decrease and permeability of granite increases with increasing temperature. Using porosity as the medium, a new wave velocity-permeability model is established with modified wave velocity-porosity formula and Kozeny-Carman formula. Under some given wave velocities and corresponding permeabilities through experiment, the permeabilities at different temperatures and wave velocities can be obtained. By comparing the experimental and the theoretical results, the proposed formulas are verified. In addition, a sensitivity analysis is performed to examine the effect of particle size, wave velocities in rock matrix, and pore fluid on permeability: permeability increases with increasing particle size, wave velocities in rock matrix, and pore fluid; the higher the rock wave velocity, the lower the effect of wave velocities in rock matrix and pore fluid on permeability.

Temperature dependence of the etch rate and selectivity of silicon nitride over silicon dioxide in remote plasma NF3/Cl2

1995 ◽  
Vol 67 (13) ◽  
pp. 1902-1904 ◽  
Author(s):  
J. Staffa ◽  
D. Hwang ◽  
B. Luther ◽  
J. Ruzyllo ◽  
R. Grant
Keyword(s):  
Silicon Nitride ◽  
Silicon Dioxide ◽  
Temperature Dependence ◽  
Etch Rate ◽  
Remote Plasma

Reaction ergodography for silicon nitride bond formation by the nitridation of silicon dioxide

1992 ◽  
Vol 96 (7) ◽  
pp. 3029-3033 ◽  
Author(s):  
Akitomo Tachibana ◽  
Yuzuru Kurosaki ◽  
Hiroyuki Fueno ◽  
Toshiaki Sera ◽  
Tokio Yamabe
Keyword(s):  
Silicon Nitride ◽  
Silicon Dioxide ◽  
Bond Formation

scholarly journals Simulation of Proton Beam Effects in Thin Insulating Films

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Ljubinko Timotijevic ◽  
Irfan Fetahovic ◽  
Djordje Lazarevic ◽  
Milos Vujisic
Keyword(s):  
Monte Carlo ◽  
Silicon Nitride ◽  
Integrated Circuits ◽  
Silicon Dioxide ◽  
Monte Carlo Simulations ◽  
Proton Energy ◽  
Transport Parameters ◽  
Insulating Layer ◽  
Insulating Films ◽  
Ultrathin Layers

Effects of exposing several insulators, commonly used for various purposes in integrated circuits, to beams of protons have been investigated. Materials considered include silicon dioxide, silicon nitride, aluminium nitride, alumina, and polycarbonate (Lexan). The passage of proton beams through ultrathin layers of these materials has been modeled by Monte Carlo simulations of particle transport. Parameters that have been varied in simulations include proton energy and insulating layer thickness. Materials are compared according to both ionizing and nonionizing effects produced by the passage of protons.

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