Nithin Chandran B S1,Brian Wyatt1,Kartik Nemani1,Matthew Boebinger2,Raymond Unocic2,Babak Anasori1
Purdue University1,Oak Ridge National Laboratory2
Nithin Chandran B S1,Brian Wyatt1,Kartik Nemani1,Matthew Boebinger2,Raymond Unocic2,Babak Anasori1
Purdue University1,Oak Ridge National Laboratory2
2D MXenes have a wide array of impressive properties due to their inherent transition metal carbide cores with abundant surface functionalities. While MXenes can be rapidly oxidized in air at high temperatures, they can be transformed into ultra-high temperature carbides when annealed under an inert atmosphere or vacuum. By annealing stacks of 2D MXene flakes, we can fabricate refractory carbides with controlled morphologies and crystal orientations. In this talk, we present our current understanding of the phase transformation of different MXenes, including Ti<sub>3</sub>C<sub>2</sub>T<i><sub>x</sub></i> and Mo<sub>2</sub>TiC<sub>2</sub>T<i><sub>x</sub></i>, by annealing them in the 600 °C to 2000 °C range under argon. We used a combination of ex-situ and in-situ characterization techniques and identified the effect of defects, such as vacancies and cation decorations, on phase stability and transformation of MXenes to refractory carbides. Our results suggest that MXenes can be used as nanosized building blocks for ultra-high temperature coatings or ceramic composite additives.