Elastic Properties of High-Symmetry Sb4O6 Cage-Molecular Crystal

The cubic-phase antimony trioxide (alpha-Sb2O3) is a room-temperature stable molecular crystal, composed of cage-like tetraantimony hexoxide (Sb4O6) molecules. Despite its versatile functionality, the van der Waals (vdW) bond-dominated nanomechanics is still unclear. Here, the bending plate-like linear behaviors of highquality alpha-Sb2O3 nanoflakes were observed using the nanoindentation method. It is found that the cage-molecular crystal owns a very low in-plane Young's modulus of 14.9 +/- 0.8 GPa and a remarkable maximum tensile strain of 6.0-8.8%, corresponding to a rupture strength of 0.89-1.31 GPa. Elucidated by the atomistic simulations, the compliant elastic modulus and the unexpectedly strong rupture strain are associated with the highsymmetry vdW bonding structure. The vdW nanomechanics is of fundamental and technological relevance to nanoelectronics.

Automated summary

The study found that alpha-Sb2O3 nanoflakes exhibit unique bending properties, with a low Young's modulus and remarkable maximum tensile strain, which are attributed to the high-symmetry vdW bonding structure. The vdW nanomechanics have fundamental and technological relevance to nanoelectronics.