@article{Fang2026, 
author = {Yuhao Fang and Wenzheng Zhang and Mingyi Tan and Daming Chen and Yanju Gu and Ao Chen and Chiyu Wang and Nan Qu and Lyu Yang and Xinghong Zhang and Yanchun Zhou},
title = {Formation and atomic-scale characterization of an interfacial β-Si3N4 nanolayer in a C/SiC composite},
year = {2026},
journal = {Journal of Advanced Ceramics},
keywords = {β-Si3N4, C/SiC interface, Atomic-resolution STEM, Electron energy-loss near-edge structure, Si-N bonding},
url = {https://www.sciopen.com/article/10.26599/JAC.2026.9221399},
doi = {10.26599/JAC.2026.9221399},
abstract = {β-Si3N4 combines attractive mechanical, thermal, and dielectric properties, yet experimental characterization of its local atomic arrangement and bonding-related electronic structure is often complicated by the sintering additives and intergranular phases present in bulk ceramics. Here, a continuous, sintering-additive-free β-Si3N4 nanolayer was formed at the C/SiC interface through reactive infiltration of molten Si into a nitrogen-containing, glucose-derived carbon framework. The nanolayer exhibits micrometer-scale lateral continuity within the examined interfacial region, with a local thickness on the order of 20 nm, providing a resolvable crystalline interior that remains accessible to site-specific atomic-scale analysis. Correlative HAADF-STEM and iDPC-STEM observations along multiple crystallographic directions resolved both the projected Si framework and the light-element N sublattice, and consistently identified the characteristic ABAB stacking and corner-sharing SiN4 tetrahedral network of β-Si3N4. The N K-edge and Si L2,3-edge electron energy-loss near-edge structures were further examined using reference spectra and density-functional-theory-based simulations. Their principal features were associated with complementary N- and Si-projected components of the hybridized unoccupied states in the tetrahedral Si-N framework. Projected densities of states, charge-density redistribution, and band-structure calculations further revealed N-weighted occupied bonding states, predominantly Si-derived unoccupied states with finite N 2p contributions, partial charge transfer from Si to N, and directional covalent bonding. Together, these results provide correlated atomic-scale structural and bonding-sensitive spectroscopic characterization of the interfacial β-Si3N4 nanolayer, with first-principles calculations supporting the interpretation of the principal ELNES features.}
}