Results 1 - 10 of 20881
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[en] We present three experimental themes and one discussion theme that proved to be suitable for introducing nanoscience through topics that can be integrated into the existing introductory physics or teacher training courses. The experimental themes include two teaching models of an atomic force microscope (AFM) and an experiment with an elastic optical grating. They are all based on simple experiments that give also quantitative results and can be explained using basic physics theory.
[en] We present the proof-of-principle experiments of a high-speed actuation method to be used in tapping-mode atomic force microscopes (AFM). In this method, we do not employ a piezotube actuator to move the tip or the sample as in conventional AFM systems, but, we utilize a Q-controlled eigenmode of a cantilever to perform the fast actuation. We show that the actuation speed can be increased even with a regular cantilever
[en] We present a scheme for small-displacement measurements using high-order Hermite-Gauss modes and balanced homodyne detection. We demonstrate its use with experimental results of displacement measurements using fundamental transverse mode TEM00 and first order transverse mode TEM10 as signal modes. The results show a factor of 1.41 improvement in measurement precision with the TEM10 mode compared with that with the TEM00 mode. This scheme has potential applications in precision metrology, atomic force microscopy, and optical imaging
[en] Highlights: • Edge modifications significantly tune electronic properties of zigzag-edged BC2N nanoribbons (ZBC2NNRs). • The O-decorated ZBC2NNRs show a ferromagnetic (FM) ground state. • The wide H-passivated ZBC2NNRs achieve an antiferromagnetic (AFM) ground state and a half-metallic character. • The band gaps of all semiconducting ZBC2NNRs decrease with increasing ribbon widths. We use first principles calculations to investigate the effects of edge modification with nonmetal species on zigzag-edged BC2N nanoribbons (ZBC2NNRs). These ZBC2NNRs show either semiconducting or metallic behaviors depending on the edge modifications and ribbon widths. We find that the O-modification induces a ferromagnetic ground state with a metallic behavior for all the ribbon widths investigated. And when the ribbon width is more than 3.32 nm (NZ ⩾ 16), an antiferromagnetic ground state with a half-metallic behavior is realized in the H-passivated ZBC2NNRs. These versatile electronic properties render the ZBC2NNRs a promising candidate material in nanoelectronics and nanospintronics.
[en] The atomic force microscopy (AFM) is a technique that is widely used to study the mechanical properties of biological samples in conditions close to natural. In particular, the technique can deliver the information about both the cell stiffness and the unbinding force of individual molecular complexes. Cell stiffness seems to be a global parameter describing the overall changes occurring in the cell structure, particularly in the cellular scaffold called cytoskeleton. The determination of the unbinding forces, acting between a single pair of molecules, brings more specific information about the interaction forces. Both types of AFM measurements can be successfully applied for the detection and quantification of the alterations of mechanical properties in cancerous cells with the special emphasis on the development of a new technique for the cancer detection on a single cell level.
[en] In tip-scan atomic force microscopy (AFM) that scans a cantilever chip in the three dimensions, the chip body is held on the Z-scanner with a holder. However, this holding is not easy for high-speed (HS) AFM because the holder that should have a small mass has to be able to clamp the cantilever chip firmly without deteriorating the Z-scanner’s fast performance, and because repeated exchange of cantilever chips should not damage the Z-scanner. This is one of the reasons that tip-scan HS-AFM has not been established, despite its advantages over sample stage-scan HS-AFM. Here, we present a novel method of cantilever chip holding which meets all conditions required for tip-scan HS-AFM. The superior performance of this novel chip holding mechanism is demonstrated by imaging of the α3β3 subcomplex of F1-ATPase in dynamic action at ∼7 frames/s
[en] We present an experimental study of coexisting p(2 × 1) and c(6 × 2) phases on an oxygen-terminated Cu(110) surface by noncontact atomic force microscopy (NC-AFM) at 78 K. Ball models of the growth processes of coexisting p(2 × 1)/c(6 × 2) phases on a terrace and near a step are proposed. We found that the p(2 × 1) and c(6 × 2) phases are grown from the super Cu atoms on both sides of O–Cu–O rows of an atomic spacing. In this paper, we summarize our investigations of an oxygen-terminated Cu(110) surface by NC-AFM employing O- and Cu-terminated tips. Also, we state several problems and issues for future investigation. (paper)