3D self-assemblies of β-Si3N4: Synthesis, characterization and growth mechanism

Abstract

In this paper, the formation of β-Si3N4 3D self-assemblies via combustion of Si-(C2F4)n-KClO4 solid mixture in nitrogen atmosphere is demonstrated. The coupling of (C2F4)n and KClO4 additives with Si powder stimulates the combustion-nitridation process and leads to the formation and 3D self-assemblies composed of β-Si3N4 prismatic crystals. The self-assemblies are classified as sheet-type, circular-type, castle-type geometry objects, high symmetry multipods and ‘crystals bouquets’ having a central junction. The formation of 3D self-assemblies is based on prismatic crystals twining process and among twinned structures, penetration, contact and circular twins were distinguished. Based on SEM and TEM results a scheme showing the growth process of self-assemblies is proposed.