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论文类型：期刊论文

发表时间：2019-02-15

发表刊物：CERAMICS INTERNATIONAL

收录刊物：SCIE

卷号：45

期号：3

页面范围：2909-2916

ISSN号：0272-8842

关键字：MgO scaffolds; B4C ultrathin films; DC arc-discharge plasma; Band

摘要：The excellent physical and chemical properties of two-dimensional (2D) ultrathin film of boron carbide (B4C) make it suitable for various applications. Nonetheless, the related fabrication strategies have not been well established yet. In this paper, the branches of dendritic magnesium oxide (MgO) nanofibers have been firstly used to serve as the template for synthesis of high-quality monolayer B4C ultrathin film. As a thermal source, DC arc-discharge plasma was adopted to co-evaporate the raw mixture target comprising of boron, graphite and magnesium oxide species. In the evaporation and subsequent condensation processes, the scaffolds of crossed MgO nanofibers were built at higher temperature prior to heterogeneous nucleation of B4C nanosheets on them. It is indicated that the kneaded B4C films can wrap MgO nanofibers into a round-shaped sphere and were entirely stretched out by removal of MgO scaffolds through a simple water-washing purification. The monolayer B4C ultrathin film is about 1.5 nm in thickness and several micrometers in length. UV-vis diffuse reflectance spectra reveal that the band gap of B4C films is similar to 1.37 eV, which is around 50% higher than that of normal B4C films. This work describes the formation mechanism of such monolayer B4C ultrathin film in aspect of nucleation/growth processes under the high-temperature plasma conditions.