Surface imaging

Yuan J-Y, Shao Z and Gao C 1991 Alternative method of imaging surface topologies of nonconducting bulk specimens by scanning tunnelling microscopy Phys. Rev. Lett. 67 863... 

Instmmentation for tern is somewhat similar to that for sem however, because of the need to keep the sample surface as clean as possible throughout the analysis to avoid imaging surface contamination as opposed to the sample surface itself, ultrahigh vacuum conditions (ca 10 -10 Pa) are needed in the sample area of the microscope. Electron sources in tern are similar to those used in sem, although primary electron beam energies needed for effective tern are higher, typically on the order of ca 100 keV. 

Maivald, P, Butt, H.J., Gould, S.A., Prater, C.B., Drake, B., Gurley, J.A., Elings, VB. and Hansma, P.K.. Using force modulation to image surface elasticities with the atomic force microscope. Nanotechnology, 2, 103-106 (1991). 

Since the introduction of scanning tunnelling microscopy, a family of scanning probe microscopies (SPMs) have been developed (Table 3.1), with three main branches resulting from three different types of probe. All of the methods have in common the ability to image surfaces in real space at nanometre or better resolution, are straightforward to implement and are relatively low in cost. 

Soon after the invention of the STM as a tool for imaging surfaces in real space, it was discovered that the microscope could also be used (or misused) for surface manipulations, that is, for nano structuring of surfaces [5]. The extremely close vicinity of the STM tip and the sample surface required by the tunnel process... 

Hutter H, Brunner C, Nikolov SG, Mittermayr C, Grasserbauer M (1996) Image surface spectroscopy for two and three dimensional characterization of materials. Fresenius J Anal Chem 355 585... 

Wickes BT, Kim Y, Castner DG (2003) Denoising and multivariate analysis of time-of-flight SIMS images. Surface Interface Anal 35 640... 

AFM has been used to image surfaces by probing both the attractive and repulsive forces experienced by the tip as a result of its proximity to the sample surface. In both modes, the probe tip is mounted on a cantilever spring. Three main designs have been employed metal foil with a splinter of diamond, a shaped tungsten wire that acts both as spring and tip, and microfabricated tip/cantilever composites. 

R. N. S. Sodhi, Time of flight secondary ion mass spectrometry (ToF SIMS) versatility in chemical and imaging surface analysis, Analyst, 129, 483 487 (2004). 

AFM can image surfaces of a wide range of biological material. 

Field emission microscopy was the first technique capable of imaging surfaces at resolution close to atomic dimensions. The pioneer in this area was E.W. Muller, who published the field emission microscope in 1936 and later the field ion microscope in 1951 [23]. Both techniques are limited to sharp tips of high melting metals (tungsten, rhenium, rhodium, iridium, and platinum), but have been extremely useful in exploring and understanding the properties of metal surfaces. We mention the structure of clean metal surfaces, defects, order/disorder phenomena,... 

Describe some of the recent developments for imaging surfaces and particles What principles do they use Name some advantages and limitations of each of the techniques. 

H. Hutter, Ch. Brunner, St. Nikolov, Ch. Mittermayer and M. Grasserbauer, Imaging surface spectroscopy for two- and three-dimensional characterisation of materials, Fresenius J. Anal. Chem., 355(5-6), 1996, 585-590. 

Aspect ratio of images Surface tension effects and mechanical strength of materials... 

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