|About this Abstract
||MS&T22: Materials Science & Technology
||Controlled Synthesis, Processing, and Applications of Structural and Functional Nanomaterials
||Mechanistic Investigation of the Formation of Transition Metal Nanocrystallites Embedded in Amorphous Silicon Nitride Nanocomposites
||Norifumi Asakuma, Shotaro Tada, Erika Kawaguchi, Motoharu Terashima, Sawao Honda, Samuel Bernard, Yuji Iwamoto
|On-Site Speaker (Planned)
We report the mechanistic investigation of the formation of transition metal (Tm) nanocrystallites during the formation of amorphous silicon nitride at a temperature as low as 400 ℃, using perhydropolysilazane (PHPS) as a preformed precursor and further coordinated by transition chloride (TmCl2, Tm = Co, Ni); thus, forming the non-noble Tm as a potential catalyst and the support in an one-step process. It was demonstrated that TmCl2 catalyzed dehydrocoupling reactions between Si-H and N-H bonds in PHPS to afford ternary silylamino groups, which resulted in the formation of a nanocomposite precursor via complex formation: Tm (II) cation of TmCl2 coordinated the ternary silylamino ligands formed in situ. It was revealed that the Tm-N bond formed by a nucleophilic attack of the N atom on the Tm(II) cation center, followed by Tm nucleation below 300 ℃, which was promoted by the decomposition of the transition metal nitride species (TmxNy).