  Recently (C.-T. Toh et al., Nature 577, 199 (2020)), the first synthesis of
free-standing monolayer amorphous carbon (MAC) was achieved. MAC is a pure
carbon structure composed of five, six, seven and eight atom rings randomly
distributed. MAC proved to be surprisingly stable and highly fracture
resistant. Its electronic properties are similar to boron nitride. In this
work, we have investigated the mechanical properties and thermal stability of
MAC models using fully-atomistic reactive molecular dynamics simulations. For
comparison purposes, the results are contrasted against pristine graphene (PG)
models of similar dimensions. Our results show that MAC and PG exhibit distinct
mechanical behavior and fracture dynamics patterns. While PG after a critical
strain threshold goes directly from elastic to brittle regimes, MAC shows
different elastic stages between these two regimes. Remarkably, MAC is
thermally stable up to 3600 K, which is close to the PG melting point. These
exceptional physical properties make MAC-based materials promising candidates
for new technologies, such as flexible electronics.
