Fabrication and properties of in situ silicon nitride nanowires reinforced porous silicon nitride (SNNWs/SN) composites

AbstractWe performed in-situ photoluminescence and Raman measurements on an anodized silicon surface in the HF/ethanol solution used for anodization. The porous silicon thereby produced, while resident in HF/ethanol, does not immediately exhibit intense photoluminescence. Intense photoluminescence develops spontaneously in HF/ethanol after 18–24 hours or with replacement of the HF/ethanol with water. These results support a quantum confinement mechanism in which exciton migration to traps and nonradiative recombination dominates the de-excitation pathways until silicon nanocrystals are physically separated and energetically decoupled by hydrofluoric acid etching or surface oxidation. The porous silicon surface, as produced by anodization, shows large differences in photoluminescence intensity and peak wavelength over millimeter distances. Parallel Raman measurements implicate nanometer-size silicon particles in the photoluminescence mechanism.

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Characterization of porous silicon nitride ceramics using bentonite as binder and sintering additive

Materials Characterization ◽

10.1016/j.matchar.2008.11.016 ◽

2009 ◽

Vol 60 (5) ◽

pp. 456-460 ◽

Cited By ~ 7

Author(s):

Guang-Peng Jiang ◽

Jian-Feng Yang ◽

Ji-Qiang Gao ◽

Koichi Niihara

Keyword(s):

Silicon Nitride ◽

Porous Silicon ◽

Sintering Additive ◽

Nitride Ceramics

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Effects of Sintering Additives on the Microstructure and Mechanical Properties of Silicon Nitride Ceramics by GPS

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.105-106.27 ◽

2010 ◽

Vol 105-106 ◽

pp. 27-30 ◽

Cited By ~ 2

Author(s):

Wei Ru Zhang ◽

Feng Sun ◽

Ting Yan Tian ◽

Xiang Hong Teng ◽

Min Chao Ru ◽

...

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Phase Transformation ◽

Silicon Nitride ◽

Porous Silicon ◽

Flexural Strength ◽

Relative Density ◽

Sintering Additives ◽

Microstructure And Mechanical Properties ◽

Nitride Ceramics

Silicon nitride ceramics were prepared by gas pressure sintering (GPS) with different sintering additives, including La2O3, Sm2O3 and Al2O3. Effect of sintering additives on the phase-transformation, microstructure and mechanical properties of porous silicon nitride ceramics was investigated. The results show that the reaction of sintering additives each other and with SiO2 had key effects on the phase-transformation, grain growing and grain boundaries. With 9MPa N2 atmosphere pressure, holding 1h at 1850°C, adding 10wt% one of the La2O3, Sm2O3, Al2O3, porous silicon nitride was prepared and the relative density was 78%, 72%, 85% respectively. The flexural strength was less than 500MPa, and the fracture toughness was less than 4.8MPam1/2. Dropping compounds sintering additives, such as La2O3+Al2O3, Sm2O3+Al2O3 effectively improves the sintering and mechanical properties. The relative density was 99.2% and 98.7% with 10wt% compounds sintering additives. The grain ratio of length to diameter was up to 1:8. The flexural strength was more than 900MPa, and the fracture toughness was more than 8.9MPam1/2.

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The development of a porous silicon nitride crossflow filter; Final report, September 1988--September 1992

10.2172/140622 ◽

1992 ◽

Cited By ~ 2

Author(s):

Keyword(s):

Silicon Nitride ◽

Porous Silicon ◽

Final Report

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