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Strength of metals at the Fermi length scale
Author(s) -
Armstrong Jason N.,
Hua Susan Z.,
Chopra Harsh Deep
Publication year - 2012
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201105541
Subject(s) - atom (system on chip) , fermi level , atomic number , atomic units , electron , condensed matter physics , chemistry , atomic physics , materials science , molecular physics , physics , quantum mechanics , computer science , embedded system
Using silver and gold, we have measured the size‐dependence of the yield strength of atomic‐sized samples as small as a single‐atom bridge, with pico‐level resolution in the applied force and displacement. The strength approaches theoretical values as the diameter of the sample becomes comparable to the Fermi wavelength of electrons (∼0.5 nm); in the limit of a single‐atom bridge, the strength is over four orders of magnitude higher than in bulk single crystals. Results provide direct evidence for Pauling's prediction of bond stiffening with reduced atomic coordination. Beginning with a single‐atom bridge, strength evolves in a staircase manner in Ag, instead of the intuitively assumed continuous approach to a saturating bulk value.Measured strength approaching theoretical (ideal) values at the Fermi length scale, corresponding to a sample made of a single‐atom Au bridge. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)