title: Crystallographic anisotropy of the resistivity size effect in single crystal tungsten nanowires.
abstract: This work demonstrates an anisotropic increase in resistivity with decreasing width in single crystal tungsten (W) nanowires having a height of 21 nm. Nanowire-widths were in the range of 15-451 nm, with the anisotropy observed for widths below 50 nm. The longitudinal directions of the nanowires coincided with the <100>, <110> and <111> orientations of the body centered cubic phase of W. The resistivity increase was observed to be minimized for the <111>-oriented single crystal nanowires, exhibiting a factor of two lower increase in resistivity at a width of ~15 nm, relative to the thin film resistivity (i.e., an infinitely wide wire). The observed anisotropy is attributed to crystallographic anisotropy of the Fermi velocity and the resultant anisotropy of the electron mean free path in W, and underscores the critical role of crystallographic orientation in nanoscale metallic conduction.
authors.affiliation: Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, USA.
authors.forename: Dooho
authors.initials: D
authors.lastname: Choi
authors.forename: Matthew
authors.initials: M
authors.lastname: Moneck
authors.forename: Xuan
authors.initials: X
authors.lastname: Liu
authors.forename: Soong Ju
authors.initials: SJ
authors.lastname: Oh
authors.forename: Cherie R
authors.initials: CR
authors.lastname: Kagan
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Coffey
authors.forename: Katayun
authors.initials: K
authors.lastname: Barmak
mesh_terms: D016880:Anisotropy; D003198:Computer Simulation; D017097:Electric Impedance; D008422:Materials Testing; D008956:Models, Chemical; D008968:Molecular Conformation; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure*; D014414:Tungsten / Q000737:chemistry*
chemical_list: D014414:Tungsten