Advanced synthesis of highly crystallized hexagonal boron nitride by coupling polymer-derived ceramics and spark plasma sintering processes—influence of the crystallization promoter and sintering temperature. (19th November 2018)

• Record Type: Journal Article
• Authors: Li, Yangdi; Garnier, Vincent; Journet, Catherine; Barjon, Julien; Loiseau, Annick; Stenger, Ingrid; Plaud, Alexandre; Toury, Bérangère; Steyer, Philippe
• Is Part Of: Nanotechnology. Volume 30:Number 3(2019)
• Publication Date: 2018-11-19
• Subjects: 2D materials -- graphene substrates -- h-BN -- spark plasma sintering -- BNNSs -- polymer-derived ceramics; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/1361-6528/aaebb4
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: Hexagonal boron nitride nanosheets (BNNSs) are promising 2D materials due to their exceptional chemical and thermal stabilities together with their electrical insulation properties. A combined synthesis method involving the polymer-derived ceramics (PDCs) route and the spark plasma sintering (SPS) process is proposed, leading to well-crystallized and pure layered h-BN crystals, prone to be exfoliated into large BNNSs. Here we focus more specifically on the influence of two key parameters of the process to be optimized: the Li3 N concentration (0–10 wt%) and the SPS temperature (1200 °C–1950 °C). The presence of Li3 N, added as crystal promoter in the pre-ceramic powder, significantly improves the crystallinity level of the product, as evidenced by XRD, SEM and Raman spectrometry. SPS temperature strongly modifies the size of the resulting h-BN flakes. The influence of SPS temperature on both purity and crystallinity is studied using cathodoluminescence. h-BN flakes larger than 200 μ m 2 (average flake area) are obtained. Few-layered BNNSs are successfully isolated, through exfoliation process.