Atomic force microscopy measurement of the Young's modulus and hardness of single LaB6 nanowires

We have employed the atomic force microscopy based (a) three-point bending and (b) nanoindentation methods to obtain the Young's modulus and hardness of single LaB(6) nanowires. The Young's modulus, E=467.1 +/- 15.8 GPa, is the same as that of the LaB(6) single crystals but larger than the sintered polycrystalline LaB(6) samples. The nanoindentation hardness of the LaB(6) nanowire is H=70.6 +/- 2.1 GPa at an indent depth of 4.6 nm, which is higher than that of the LaB(6) single crystals, LaB(6) polycrystals, and W metals. A superior resistance against thermal vibration, field modification, and ion bombardment is expected for the LaB(6) nanowires as a field-emission point electron source.(c) 2008 American Institue of Physics.