4:15 PM - 4:30 PM
▲ [16p-Z15-10] Mechanical properties of atomic bonds in Pt atomic chains measured by TEM coupled with a quartz resonator
Keywords:TEM, mechanical properties, atomic chains
Atomic chains have shown unique structural, electronic, and magnetic properties and attract much research interest. The electrical or magnetic properties has been reported to be tuned by controlling the length of the atomic chains, which indicate the mechanical properties is very important not only to the fundamental research interest in the field of physics chemistry and material science, but also to their potential applications such as future advanced devices. However, the mechanical properties of atomic chains have not been clarified experimentally. To solve this problem, we developed an in-situ TEM holder with a quartz resonator as force sensor to measure the mechanical properties of atomic chains when observing their atomic configurations.
We use a quartz length-extension resonator (LER) to resolve the stiffness of platinum (Pt) atomic chains by measure the frequency shift. The oscillation amplitude can be controlled to as low as ~25pm to avoid the plastic deformation. The atomic configurations can be obtained from the TEM image when measure the conductance and stiffness (fig. 1). We found that the stiffness of an atomic chain various with the number of atoms in a chain (fig. 2). The stiffness of each bond in the chain can be identified after remove the contribution of the base part [2]. We found that the middle bond stiffness (25N/m) was slightly higher than that of the bond connect to the suspending tip (23N/m). In addition, the maximum elastic strain in the chain is as large as 24%. These results are briefly explained by the concept of “string tension”.
We use a quartz length-extension resonator (LER) to resolve the stiffness of platinum (Pt) atomic chains by measure the frequency shift. The oscillation amplitude can be controlled to as low as ~25pm to avoid the plastic deformation. The atomic configurations can be obtained from the TEM image when measure the conductance and stiffness (fig. 1). We found that the stiffness of an atomic chain various with the number of atoms in a chain (fig. 2). The stiffness of each bond in the chain can be identified after remove the contribution of the base part [2]. We found that the middle bond stiffness (25N/m) was slightly higher than that of the bond connect to the suspending tip (23N/m). In addition, the maximum elastic strain in the chain is as large as 24%. These results are briefly explained by the concept of “string tension”.