Abstract
Real-time deformation of individual multiwalled boron nitride nanotubes (BNNTs) was investigated using an atomic force microscopy (AFM) stage installed inside the chamber of a transmission electron microscopy (TEM) system. These
in situ
AFM-TEM experiments were conducted in following two deformation regimes: a small-angle
(
∼
65
°
)
and a large-angle
(
∼
120
°
)
cyclic bending process. BNNTs survived from the low-angle test and their modulus was determined as
∼
0.5
TPa
. Fracture failure of individual BNNTs was discovered in the large-angle cyclic bending. The brittle failure mechanism was initiated from the outermost walls and propagated toward the tubular axis with discrete drops of applied forces.