Temperature and size dependent mechanical properties of vapor synthesized zinc tungstate nanowires

Monoclinic structured zinc tungstate (ZnWO) nanowires were synthesized using a simple physical vapor deposition procedure. The nanowires grew along the [001] direction and exhibited faceted surfaces. The Young's modulus of the nanowires was characterized by a resonant method based on laser Doppler vibrometry. The modulus of nanowires with thicknesses greater than ∼120 nm was close to that of their bulk counterparts, whilst the modulus of those with thicknesses in the range of 120 nm–67 nm decreased by ∼10%. Their modulus was also characterized over a temperature range from 300 to 650 K, and a dependency with temperature was observed. The fracture strain of the nanowires was characterized using a bending test based on optical microscope nanomanipulation in ambient atmosphere. The fracture strain of the nanowires slightly increased from 4% to 5% as their widths decreased from 325 to 50 nm, and no evidence of plastic deformation is observed during the direct fracture analysis by transmission electron microscope.