Mechanical properties of Pt monatomic chains

Abstract

The mechanical properties of Pt monatomic chains were investigated by a simultaneous measurement of effective stiffness and conductance using our recently developed mechanically controllable break junction technique with a tuning fork as a force sensor. When stretching a monatomic contact ͑two-atom chain͒, the stiffness and conductance increases at the early stage of stretching and then decreases just before breaking, which is attributed to a transition of the chain configuration and bond weakening. A statistical analysis was made to investigate the mechanical properties of monatomic chains. The average stiffness shows minima at the peak positions of the length histogram. From this result, we conclude that the peaks in the length histogram are a measure of the number of atoms in the chains and that the chains break from a strained state. Additionally, we find that the smaller the initial stiffness of the chain is, the longer the chain becomes. This shows that softer chains can be stretched longer.

Atomic configuration, conductance, and tensile force of platinum wires of single-atom width

“…It was reported that the Young's modulus of Au ASWs is 47-116 GPa. 50 From the elongation length and corresponding farce increase in time f and g, we estimated the stiffness of the three-atom Pt ASW observed to be 5 Ϯ 1 N/ m. This value is at least six times larger than the stiffness of Pt ASWs with the same length ͑0.8 N/m͒, 37 whereas it is comparable with a stiffness of Au ASWs ͑5.8 N/m͒. 5 As shown in Fig.…”

“…29,32,54,55 As previously reported, peaks are observed at 1.3-1.8G 0 in conductance histograms when pure Pt NCs are retracted in ultrahigh vacuum. 32,36,37 On the other hand, peaks near 0.2 and ϳ0.9G 0 are observed beside a trough near 0.5G 0 when Pt NCs are examined in a hydrogen atmosphere. 32,55 In accordance with these previous results, we classified the Pt ASWs observed in this study, since a hydrogen molecules is not imaged by HRTEM ͑Ref.…”

“…15 In conductance histograms of Pt and Ir NCs, peaks are not observed at quantized values, and the peaks are wider than those of Au NCs. 4,6,7,13,[29][30][31][32][33][34][35][36][37] The deviation from quantized values is interpreted on the basis of inelastic scattering of electrons at 5d orbitals. 13,33,38,39 A relationship between the conductance and length of ASWs was reported; for Au, Pt, and Ir ASWs, their conductance oscillates depending on parity in the number of constituent atoms.…”

Probing the Orbital Origin of Conductance Oscillations in Atomic Chains

“…Atomic chains are appealing systems for the study of a large variety of phenomena, including atomic scale magnetism [17][18][19] , nanoelectromechanics 20,21 , and quantum effects in one dimension [22][23][24][25] . Chains of atoms suspended between two electrodes are particularly interesting systems for the study of electronic transport due to their relative simplicity.…”

“…We start by examining the structural and conductance properties of atomic chains that are formed when a metallic wire with a narrow constriction is pulled apart. Experiments were performed on Au and Pt wires using a break junction setup 36 which the tensile forces in the chain amount to a degree where it either breaks or an additional atom is pulled into the chain 20,21 . The peak separation (2.6±0.2Å for Au and 2.0±0.2Å for Pt) indicates the average distance by which the chain is stretched before another atom is added to the chain 26 .…”