Explosion Phase Formation of Nanocrystalline Boron Nitrides Upon Pulsed-Laser-Induced Liquid/Solid Interfacial Reaction

Abstract

Boron nitride (BN) nanocrystals with explosion (E) phase were prepared by a novel laser-assisted materials fabrication, i.e., pulsed-laser-induced liquid (acetone)/solid (hexagonal boron nitride bulk) interfacial reaction at normal temperature and pressure. Typical diameters of these synthesized quasi-spherical BN nanocrystals were in the range of 30 to 80 nm. Transmission electron microscopy, x-ray diffraction, and Fourier transformed infrared spectroscopy were used to identify the morphologies and structures of the synthesized nanocrystals. Additionally, we proposed the formation mechanism of cubic-BN and E-BN nanocrystals upon pulsed-laser-induced liquid/solid interfacial reaction, in which both liquid and solid were simultaneously involved.

Synthesis and optical properties of purified translucent, orthorhombic boron nitride films

“…The typical XRD pattern of the sample is shown in Fig. 2, and the majority of the peaks were similar to the observations in the previous literature [4,5,7,9,14]. The data are analyzed by commercial MDI Jade 5.0 ( Table 1).…”

“…Since the main peaks in the corresponding X-ray diffraction (XRD) pattern can be assigned to orthorhombic structure, the eBN is also called as oBN [6,7]. Thereafter, various non-explosion methods [8][9][10][11] have been proposed to synthesize oBN (eBN). However, the impurity phases of hBN and/or cBN generally appeared in those products.…”

Laser ablation in liquids: Applications in the synthesis of nanocrystals

“…Researchers have studied the transformation from hexagonal BN to c-BN by laser irradiating a solid target in vacuum or diluted gases, aiming at the preparation of a c-BN films or c-BN crystals [233][234][235]. Interestingly, nanocrystals of c-BN have been synthesized by Nd:YAG pulsed laser ablating a h-BN target in acetone [236,237], and the corresponding synthesis mechanism has been pursued [190,199]. Therefore, in this section, we outline the mechanism of the c-BN nanocrystal synthesized by PLA of an h-BN target in a liquid environment.…”

“…Furthermore, the intermediate phase of the conversion from graphite to diamond was also obtained in experimental [23]. Similarly, nanocrystals of the explosion boron nitride (E-BN) and c-BN were synthesized simultaneously by PLA of an h-BN target in acetone [236,237]. Note that, both hexagonal diamond and E-BN are metastable phase to cubic diamond and c-BN.…”

From nanocrystal synthesis to functional nanostructure fabrication: laser ablation in liquid

“…[19][20][21][22][23][24] For instance, researchers first selected diamond nanoparticles as the synthesized object by using LAL, [25][26][27][28] because one side that the properties of diamond are quite extreme compared with that of other materials, and another side that the synthesis of diamonds under conditions of normal temperature and pressure is not predicted by the equilibrium thermodynamic phase diagram of carbon. Accordingly, laser ablation of a solid target in a confined liquid has been demonstrated to be an effective and general route toward nanocrystal and nanostructure synthesis, especially for synthesizing nanocrystals with metastable phases, such as diamond and related materials, [29][30][31][32] and an immiscible alloying phase. 33 In the past decade, there have been many investigations involved in the size control of metallic nanoparticles (note that in some investigations the synthesis of nanoparticles by laser ablation is called laser ablation synthesis (LAS)), [34][35][36] colloid formation with the influence of laser wavelength and focus, [37][38][39] and nanostructure fabrication upon laser ablation of a solid target in liquid.…”