Imaging modes, optical microscop

Figure 7.15 Chemical structure of the 2,6-bis(l methylbenzimidazolyl) pyridine (Mebip) end-capped monomer (24) and optical microscopic images of its resulting MSP gels (8 wt% in acetonitrile) formed with (a) Zn(C104)2 and (b) Zn(C104)2/La(C104)3 (mole ratio = 97 2) obtained using a laser scanning confocal microscope operated in transmitted mode (Weng et al. 2006).

Energetic particles react with solid matter in a variety of ways. Low-energy particles in the solar wind ( 1 KeV/nucleon) are implanted into solids to depths of 50 nm. Energetic heavy particles penetrate more deeply and disrupt the crystal lattice, leaving behind tracks that can be imaged by or chemically etched and observed in an optical microscope. Particles with energies of several MeV or more may induce a nuclear reaction. The two main modes of production of cosmogenic nuclides are spallation reactions and neutron capture. 

This chapter describes briefly the basic construction and characteristics of the modern transmission electron microscope and discusses its principal modes of operation. Because the electron microscope is an analogue of the optical (or light) microscope, we also consider briefly the basic features of the optical microscope this will also provide a link with our earlier discussion of the optical principles of image formation by a lens. 

Hatano H, Inouye Y, Kawata S (1997) Near-field optical microscope with a multiheight scanning-imaging mode. Opt Lett 22 1532... 

Unlike an optical microscope, a scanning electron microscope can reach very high depths of field (it is, for example, possible to obtain a sharp image of all the points of a cube or sphere occupying the entire image). The detection mode employed, allowing the observer to see into holes or behind peaks, enables this field depth to be exploited to a maximum. 

The principle involves using X-rays (beam of electrons) to image atomic structures. The very short wavelengths allow much higher resolution than with a standard optical microscope. There are several types of electron microscope which allow different types of image to be formed. They operate in either transmission mode (electrons pass through the sample) or reflection mode (electrons are reflected from the surface)... 

FIG. 20 An optical microscope image of a polyaniline pattern deposited on a gold substrate using a 10 /am Pt UME in the microreagent mode. (From Ref. 40.) Figure B is a magnification of part of Figure A. 

Operation of a SIMS instrument resembles both that of an isotope ratio mass spectrometer and an electron microscope. Most SIMS instruments include an optical microscope so that the sample can be directly viewed during analysis, which allows for accurate positioning of the area of interest on the sample. Data can be in the standard mode used for other types of mass spectrometers in which ions are produced and the mass spectrum is analyzed by scanning or peak-hopping. This mode is sometimes called the microprobe mode in SIMS. Another application for SIMS is the acquisition of ion-images. This mode is called the microscope mode because the SIMS is operated as an ion microscope. 

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