International researchers led by Osaka University develop a microscopy technique to probe materials at the subatomic scale in multiple directions simultaneously
Atomic force microscopy (AFM) is an extremely sensitive technique that allows us to image materials and/or characterize their physical properties on the atomic scale by sensing the force above material surfaces using a precisely controlled tip. However, conventional AFM only provides the surface normal component of the force (the Z direction) and ignores the components parallel to the surface (the X and Y directions).
To fully characterize materials used in nanoscale devices, it is necessary to obtain information about parameters with directionality, such as electronic, magnetic, and elastic properties, in more than just the Z direction.
That is, it is desirable to measure these parameters in the X and Y directions parallel to the surface of a material as well. Measuring the distribution of such material parameters on the atomic scale will increase our understanding of chemical composition and reactions, surface morphology, molecular manipulation, and nanomachine operation.
A research group at Osaka University has recently developed an AFM-based approach called "bimodal AFM" to obtain information about material surfaces in the X, Y, and Z directions (that is, in three dimensions) on the subatomic scale.
The researchers measured the total force between an AFM tip and material surface in the X, Y, and Z directions using a germanium (Ge) surface as a substrate. Their collaborative partner, the Institute of Physics of the Slovak Academy of Sciences, contributed computer simulations of the tip-surface interactions. The bimodal AFM approach was recently reported in Nature Physics.
"A clean Ge(001) surface has alternately aligned anisotropic dimers, which are rotated by 90° across the step, meaning they show a two-domain structure," explains first author Yoshitaka Naitoh. "We probed the force fields from each domain in the vertical direction by oscillating the AFM tip at the flexural resonance frequency and in the parallel direction by oscillating it at the torsional one."
The team first expressed the force components as vectors, providing the vector distribution above the surface at the subatomic scale. The computer simulation supported the experimental results and shed light on the nature of chemical tip termination and morphology and, in particular, helped to clarify the outstanding questions regarding the tip-surface distances in the experiment.
"We measured the magnitude and direction of the force between the AFM tip and Ge surface on a subatomic scale in three dimensions," says Naitoh. "Such measurements will aid understanding of the structure and chemical reactions of functionalized surfaces."
The developed bimodal AFM approach will allow researchers to investigate the physical properties of materials in greater detail on the nanoscale, which should facilitate development of devices, nanotechnology, and friction/lubrication systems.
Saori Obayashi | EurekAlert!
Engineers develop smart material that changes stiffness when twisted or bent
15.02.2018 | Iowa State University
Breaking local symmetry: Why water freezes but silica forms a glass
14.02.2018 | Institute of Industrial Science, The University of Tokyo
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).
Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
16.02.2018 | Information Technology
16.02.2018 | Health and Medicine
16.02.2018 | Physics and Astronomy