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Microstructural evolution of amorphous Si 2 BC 3 N nanopowders upon heating at high temperatures: High pressures reverse the nucleation order of SiC and BN (C)
Author(s) -
Liang Bin,
Jia Dechang,
Liao Xingqi,
Zhu Qishuai,
Chen Qingqing,
Yang Zhihua,
Tian Feng,
Li Xiaoyun,
Zhou Yu
Publication year - 2018
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.15566
Subject(s) - amorphous solid , nucleation , materials science , crystallization , x ray photoelectron spectroscopy , microstructure , chemical engineering , crystallography , thermodynamics , composite material , chemistry , engineering , physics
Amorphous Si 2 BC 3 N nanopowders ( NP s) were heated at 1000‐1700°C temperatures for 30 minutes in 1 atm N 2 . The changes in phases, chemical bonds, and microstructures were investigated by XRD , XPS , NMR , TEM , and first‐principles calculation. Increases in heating temperatures lead to the nucleation and growth of SiC and BN (C) grains, along with partial transformation of SiC 4 units from amorphous to β/α‐SiC, and collapse of B–C–N bonds. SiC nucleates prior to BN (C) at 1 atm, while it goes in the opposite order at high pressures (≥1 GP a). High pressures also shift the initial temperatures of crystallization of amorphous Si 2 BC 3 N NP s from 1400°C (1 atm) to 1150°C (5 GPa).