Strength and Fracture Behavior of Ultrathin Pt Wires

Ultrathin metallic wires having defects may show much lower strength compared to the strength of the wire material. To characterize ultrathin Pt wires having the nominal diameter of 625 nm, tensile test of the wires was performed by developing a testing platform and a gripping technology. Fracture stress determined by the tensile test showed much higher value compared with that of bulk Pt. However, the fracture stress of some of the wires was lower than the yield stress of the wire determined by the bending test. From the observation of the fracture surfaces, it was found that the lower fracture stress of the wires was due to the defects in the wires and such wires showed brittle fracture behavior.