Synthesis and material properties of polymer-derived niobium carbide and niobium nitride nanocrystalline ceramics
نویسندگان
چکیده
Nanocrystalline niobium carbide (NbC) ceramics and carbide-niobium nitride (NbC/NbN) composites were synthesized at low temperatures without high-pressure sintering using a single-step polymer-derived approach from meltable pre-ceramic blend. Niobium hydride (NbH5) 1,2,4,5-tetrakis(phenylethynyl)benzene (TPEB) reacted 1500 °C under argon or nitrogen in tube furnace to form NbC NbC/NbN with high purities nanosized grains. Superconductivity measurements indicated that exhibited mixed phase system two distinct Tc values, higher elemental content within solids yielded lower Tc. The resulting ceramic monoliths homogeneous morphologies controllable amounts of free carbon the composite matrix. demonstrated good air oxidation stability up 450 °C.
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ژورنال
عنوان ژورنال: Ceramics International
سال: 2021
ISSN: ['0272-8842', '1873-3956']
DOI: https://doi.org/10.1016/j.ceramint.2020.08.232