Effect of carbon on the growth of TaC crystal derived from organometallic precursors

• Published in: Hanʼguk Seramik Hakhoe chi Vol. 58; no. 1; pp. 62 - 68
• Main Authors: Lee, Yoonjoo, Kang, Philjae, Jung, Sooyong, Bae, Seonggun, Kim, Joungil, Lee, Manyoung, Shin, Dong-Geun
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 2021
• Subjects: Ceramics; Chemistry and Materials Science; Composites; Glass; Materials Science; Natural Materials; Original Article; Residual carbon; Crystal growth; Tantalium carbide; TaC
• ISSN: 1229-7801; 2234-0491
• DOI: 10.1007/s43207-020-00071-8

TaC, which is an ultra-high-temperature structural material, was derived from two types of organometallic precursors: Me 3 CCH = Ta(CH 2 CMe 3 ) 3 and Cp*-TaMe 4 . Both compounds are kinds of single-source precursors composed only of tantalum, carbon, and hydrogen, which should be converted into carbide material without oxygen contamination. The carbide material was formed through several processes such as pyrolysis, nucleation, and crystal growth, which are dependent on heat treatment temperature. However, organometallic precursor usually leaves residual carbon, and the crystallization of carbide is affected by the carbon. In this study, two types of organometallic precursors containing different amounts of carbon in the organic part were used to prepare TaC, and the crystallization behavior of TaC in rich carbon was investigated. The amount of residual carbon was estimated by thermogravimetry (TG) analysis, and the TaC crystals were characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Nano-sized TaC particles were obtained by heat treatment without any by-products but with excess carbon. The TaC crystal was formed starting from 1300 °C, but the crystals grew better with less carbon, while the carbon barrier prevented agglomeration of the atoms.