NanoVac-AFM

NanoVac-AFM
Rate : 1

The advanced nanotechnologies development and thriving possess a great deal to the microscopy imaging equipment capable of material characterization in nanoscale. One of these imaging equipment is scanning probe microscopy (SPM) which was introduced with the dawn of 1980s and quickly afterwards became of the main instruments for nanomaterial imaging. Unlike conventional imaging methods (optical and electron microscopy) which striking and reflection/diffraction of just beams of light and electrons from sample surface are responsible for imaging, this relatively new technology uses a mechanical probe with a very sharp tip (ideally, the tip of probe have one atom) to lightly touch the surface physically. This physical touch leads to detection and point-to-point data recording from surface features like topography, surface chemistry, and elastic modulus. So, with the completion of scanning process of all surface points, the resulting image can be reconstructed by analyzing the recorded data using computer-based software. The reconstructed images are basically three-dimensional images and the lateral and vertical resolution can be better than 0.1 nm. To achieve this level of precision, the probe scanning over the surface must be conducted by piezoelectric-lever actuator in three main direction X, Y Z.
The most popular type of SPM is atomic force microscopy (AFM), in which variation of near-field forces between the probe-surface atoms, and consequently, deflection of probe, are used to reveal the surface features. The most typical method for sensing the probe deflections, is the laser beam reflection. In this method, a laser beam reflected from the back side of the probe, stimulate an array of photodiodes, producing an electrical signal. So, any change in near-field forces leads to change in striking position of the laser beam in the photodiodes plane. Depending on which surface feature is desired, the imaging (operational) modes may differ. In each imaging mode, a module called feedback loop circuit is tried to maintain constant one parameter in expense of adjusting another parameter. For example in static contact mode (the simplest suitable mode for obtaining topographic imaging), the feedback circuit uses probe deflection signals as an input to send corrective instructions as an output for piezoelectric actuator so that the probe deflection remains constant. A computer-based software uses these output instructions to reconstruct into topographic images. On the other hand, for obtaining phase contrast, other imaging modes like tapping and force modulation must be utilized. In such modes, the probe oscillates at a designated frequency near the surface, and the feedback loop tries to maintain a set value of amplitude of oscillation during scanning. Because of the difference in mechanical properties (like stiffness, hardness & …) between the different phases, the output of feedback circuit, if properly translated, leads to phase contrast images.
Note that the resulting images and colors in SPM are artificial and processed, so they must be interpreted carefully. Meanwhile, making correct adjustment of operational parameters is necessary for obtaining non-defect images. In this regard, operator's experience will be very useful.
AFM NanoVac with a stainless steel container is capable to imaging in vacuum, under controlled atmospheres and different gas pressures. Getting rid of dust, interfering particles, and water molecules under vacuum conditions leads to high quality imaging. For those researchers whose aim is to image in mode of Frequency Modulation or other modes entailing transfer of electrical current, the AFM NanoVac is a premium choice. Operatingunder vacuum conditions provides an opportunity that the electrical characteristics of material (e.g. surface potential, surface electrical current, and I-V curves), without being affected by unintentionally oxidation, could bemeasured with higher precision compared to other methods. Indeed, all imaging modes supported by the apparatus of AFM Multi Mode, are also available in the AFM NanoVac.
The only new imaging mode (compared to AFM Multi Mode), is Frequency Modulation (FM). In this mode, modulation using of frequency instead of amplitude under vacuum condition results in higher quality of imaging. So AFM NanoVac could be regarded as a comprehensive Nanoscopy tool which is updated to exploit vacuum conditions for quality improvement in imaging.
AFM NanoVac is a professional tool which enables imaging under vacuum and other controlled atmospheres. It uses H-A11 head, S-C2 scanner, and C-2NFP in its design. The optional modules of HighSpeed, Motorized Head H-A11, S-C3, S-C4, and S-C5 have been also offered by the manufacturer. Vacuum is applied by means of an apparatus equipped with vacuum pump (compatible with well-known pump e.g. Leybold TriVac) and Vacuum gauge (compatible with well-known
gauge e.g. Leybold Pirani). More details about this apparatus are listed in the
Table.
filereader.php?p1=main_c4ca4238a0b923820
filereader.php?p1=main_c4ca4238a0b923820
filereader.php?p1=main_c4ca4238a0b923820
Atomic force microscopy (AFM) is a unique tool for nanomaterial imaging, characterizing, and even manipulation. AFM can generate images at atomic resolution with angstrom scale (lateral and vertical resolution can be better than 0.1 nm).
  • It is advised to use the lower floor for installation of AFM apparatus, preferably behind pillars.
  • Avoid walking around the apparatus while AFM operating.
  • Laboratory must be protected from dust and ash.
  • Acoustic pollution and mechanical noise beside the apparatus must be minimized.
  • The apparatus must be installed and placed at an enough distance from noise-making systems.
  • Use proper power cable along UPS system.
  • Ensure a good connection of earth cable

Product Standard

  • NanoScale Certification

    Standard Date : 2017/03/08

    Expire Date : 2020/03/07

Opinion

Opinion

Reply to Return

Name
Email
Comment
Captcha (Case sensitive)