. | . |
Three-dimensional direction-dependent force measurement at the subatomic scale by Staff Writers Osaka, Japan (SPX) May 17, 2017
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.
Berkeley CA (SPX) May 17, 2017 Scientists have greatly expanded the range of functional temperatures for ferroelectrics, a key material used in a variety of everyday applications, by creating the first-ever polarization gradient in a thin film. The achievement, reported May 10 in Nature Communications by researchers at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), paves the way for dev ... read more Related Links Osaka University Space Technology News - Applications and Research
|
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |