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Ionic interdiffusion as interaction mechanism between Al and Si3N4

Adabifiroozjaei, E ; Sharif University of Technology | 2019

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  1. Type of Document: Article
  2. DOI: 10.1111/jace.16358
  3. Publisher: Blackwell Publishing Inc , 2019
  4. Abstract:
  5. Al-Si3N4 couples were heat-treated at 850-1150°C for 250 hours. The thickness of the interacted area was measured by scanning electron microscopy (SEM) and scanning/transmission electron microscopy (TEM/STEM). The interaction rate increases exponentially with inverse temperature, with an activation energy of 194.23 kJ/mol and diffusion pre-coefficient of 5 × 10−9 m2/s, indicating that the interaction is diffusion-dependent. As the results showed, the interfacial area is comprised of Al alloy channels, Si precipitates, and AlN grains. Al-Si transfer through the solid solution (Si3-xAlxN4-y) at the interface of Al alloy and β-Si3N4 grains controls the kinetic of the interaction. When concentration of Al in solid solution exceeds a certain amount, it undergoes a topotactic phase transformation to form Al1-xSixN1+y (viz., AlN). Next, the Al1-xSixN1+y grains detach from the β-Si3N4 grains and subsequently new Al-Si3N4 interfaces are established. These interfaces repeat the interaction process, continuing until all the reactant is depleted. Thus, the interaction kinetics consist of a sequence of associated parabolic stages, precluding the observation of parabolic kinetics. © 2019 The American Ceramic Society
  6. Keywords:
  7. Al-Si interdiffusion ; Al-Si3N4 interface ; kinetics ; Activation energy ; Aluminum nitride ; Enzyme kinetics ; III-V semiconductors ; Kinetics ; Scanning electron microscopy ; Solid solutions ; Interaction kinetics ; Interaction mechanisms ; Interaction process ; Interfacial areas ; Inverse temperatures ; Parabolic kinetics ; Si interdiffusion ; Topotactic transformation ; Aluminum alloys
  8. Source: Journal of the American Ceramic Society ; Volume 102, Issue 8 , 2019 , Pages 4835-4847 ; 00027820 (ISSN)
  9. URL: https://ceramics.onlinelibrary.wiley.com/doi/abs/10.1111/jace.16358