Nanomechanics of Single Crystalline Tungsten Nanowires

Abstract

Single crystalline tungsten nanowires were prepared from directionally solidified NiAl-W alloys by a chemical release from the resulting binary phase material. Electron back scatter diffraction (EBSD) proves that they are single crystals having identical crystallographic orientation. Mechanical investigations such as bending tests, lateral force measurements, and mechanical resonance measurements were performed on 100–300 nm diameter wires. The wires could be either directly employed using micro tweezers, as a singly clamped nanowire or in a doubly clamped nanobridge. The mechanical tests exhibit a surprisingly high flexibility for such a brittle material resulting from the small dimensions. Force displacement measurements on singly clamped W nanowires by an AFM measurement allowed the determination of a Young's modulus of 332 GPa very close to the bulk value of 355 GPa. Doubly clamped W nanowires were employed as resonant oscillating nanowires in a magnetomotively driven resonator running at 117 kHz. The Young's modulus determined from this setup was found to be higher 450 GPa which is likely to be an artefact resulting from the shift of the resonance frequency by an additional mass loading.

Preparation and specific properties of single crystalline metallic nanowires

“…The finite element model shows that these effects have to be taken into account for accurate determination of the mechanical properties. Similar configuration was used to determine the Young's modulus of W NWs [68]. This time a single NW was contacted directly by writing the pads using Pt deposition by the focused ion beam (FIB) technique.…”

“…6 Applications 6.1 NEMS W NWs were used to construct and characterize nanoelectromechanical system (NEMS) [68]. The NEMS were produced by a method combining photo and electron beam lithography.…”

Surface dislocation nucleation mediated deformation and ultrahigh strength in sub-10-nm gold nanowires

“…Early studies of quantitative mechanical testing of one-dimensional (1-D) nanostructures were primarily carried out ex situ, using techniques such as nanoindentation [1], resonant oscillation [6], and atomic force microscopy (AFM) deflection [7] tests. These generally lack real time structural monitoring, and do not permit a one-to-one correlation between mechanical data and internal structural evolution.…”

Downsizing of single crystalline high aspect ratio tungsten nanowires

“…Tungsten nanowires, due to their unique material properties are powerful tools, for example, for pH measurements in small cavities as presented by Fenster et al , for studies on the nanomechanics of tungsten investigated by Cimalla et al , or as model systems for studying the Lotus effect .…”