Mechanism of SiC crystals growth on {100} and {111} diamond surfaces upon microwave heating

Abstract

The subject of this work is focused on characterization of the microstructures and orientations of SiC crystals synthesized in diamond-SiC-Si composites using reactive microwave sintering. The SiC crystals grown on the surfaces of diamonds have either shapes of cubes or hexagonal prisms, dependent on crystallographic orientation of diamond. The selection of a specified plane in diamond lattice for the TEM investigations IntroductionDiamond-SiC composites are considered one of the most promising materials for thermal management applications. In contrast with metal-based diamond composites, diamond-SiC potentially combine high thermal conductivity and relatively low coefficient of thermal expansion of two phases each having a low density. Chemical bonding between the diamond particles and the SiC should be provided by a reaction between carbon and silicon to form 'bridges' structurally integrated with diamond. However, the thermal resistance of SiC-diamond interfaces should be minimised to ensure efficient heat transport in the interconnected diamonds [1,2]. This can be achieved by providing defect-free, coherent interfaces between the diamond and the SiC lattices. It should be noted that the SiC crystals can grow on diamond either in an ordered fashion, resulting in highly strained epitaxial layers, low energy semi-coherent configurations [3,4] or through high-misfit interfaces with lattice defects minimizing the strain energy [5]. Numerous investigations have been carried out on the structure of SiCdiamond interfaces [5][6][7][8][9]. However, to the best knowledge of the authors, the growth mechanism of SiC crystals grown on differently oriented diamond surfaces has not been studied and experimentally verified.The diamond-SiC composites can be fabricated via hightemperature high-pressure sintering of diamond and Si [6-9], infiltration of diamond compacts with precursor gas [10] and more recently by microwave reactive sintering of diamondsilicon powders mixtures [11,12]. In contrast to the conventional processes, microwave sintering has the advantage of internal and phase-selective heat generation which offers high sintering rates [13]. Since silicon has a much higher dielectric loss than diamond, it more readily absorbs microwave energy and is preferentially heated to temperatures above its melting point [14]. The higher heating rate facilitated

One-Step Microwave Synthesis of New Hybrid Phosphor (CSSC) for White Light-Emitting Diodes

“…Our previous works have demonstrated that microwave synthesis offers several advantages, such as reduced time, temperature, and energy costs during the synthesis process [18][19][20][21][22]. Additionally, the application of microwave energy to radio-absorbing materials, by means of the ponderomotive effect and electrodiffusion, enhances the characteristics of the phosphors [23][24][25][26][27][28].…”

Heteroepitaxial CVD Growth of 3C-SiC on Diamond Substrate

“…Very little work can be found in the literature on this topic. For instance, some works present the formation of SiC on top of diamond by the reaction of liquid silicon with diamond [1,2] or by the interaction between silicon and diamond under high pressure [3,4]. More recently, some of the present authors tried growing SiC on diamond by vapor liquid solid (VLS) transport but the deposit was polycrystalline [5].…”

Diamond as substrate for 3C‐SiC growth: A TEM study

“…In particular, it can be an alternative to improve local technological problems as ohmic contacts as Al/Si [2,3], Au/Ta [4], or Mo [5]. Nevertheless, just a few authors have studied SiC growth on diamond [6,7] most probably due to the difficulties related to this heterosystem. One of the main reasons is that diamond, as substrate, usually generates rough interface at the nanometric scale [8] due the difficulty of polishing diamond.…”