Nomarski interference contrast

Fig. 1 Photomicrograph of sample EZP30 viewed under the Nomarski interference contrast. The bright phase is ZrP and the light-dark phase is epoxy resin. The pure epoxy layer is on the far right and the direction of epoxy infiltration is from right to left.

Figure 1. DN-4FB plane-strain damage zone of epoxy that has been modified with core-shell rubber. Top ROM image obtained under Nomarski interference contrast. Bottom TEM image of the croids in the plane-strain region. In both images the crack propagates from the upper right to the upper left.

Fig. 5.17. An example of secondary buckling leading to a wrinkled shape in a circular blister in a SiC thin film on a (100) Si substrate, as revealed by Nomarski interference contrast microscopy. Reproduced with permission from Argon et al.

Absorption microscopy is the conventional transmitted-light type. Retardation microscopy includes Nomarski interference-contrast (DIC), phase-contrast and polarization. Reflection microscopy includes darkground. 

Accessories greatly enhance the light microscope s ability to resolve detail, differentiate between compositions, or increase contrast. Any microsco-pist who has attempted to observe thin coatings on paper, e.g., ink lines, with the SEM soon returns to die light microscope. The Nomarski interference contrast system on a reflected light microscope gives excellent rendition of... 

Fig. 2. Differential interference contrast (Nomarski) microscope, showing exaggerated light path (12).

Nomarski differential interference contrast microscopy is an alternative to phase contrast microscopy which gives an almost three... 

Nomarski microscopy is an examination mode using differential interference contrast (DIC). The images that DIC produces are deceptively three-dimensional with apparent shadows and a relief-like appearance. Nomarski microscopy also uses polarized light with the polarizer and the analyzer arranged as in the polarized light mode. In addition, double quartz prisms ( Wollaston prisms or DIC prisms) are used to split polarized light and generate a phase difference. 

Microscopy with differential interference optics (e.g., Zeiss-Nomarski amplitude-contrast optics Webster et al., 1974). 

Hie most important optical technique for examining semiconductor wafer surfaces is the differential interference contrast microscopy method of Nomarski (N-DIC). First described in 1952, DIG... 

To understand the release mechanism, cryomicrotomy was used to slice 10 m-thick sections throughout the matrices. Viewed under an optical microscope, polymer films cast without proteins appeared as nonporous sheets. Matrices cast with proteins and sectioned prior to release displayed areas of either polymer or protein. Matrices initially cast with proteins and released to exhaustion (e.g., greater than 5 months) appeared as porous films. Pores with diameters as large as 100 /xm, the size of the protein particles, were observed. The structures visualized were also confirmed by Nomarski (differential interference contrast microscopy). It appeared that although pure polymer films were impermeable to macromolecules (2), molecules incorporated in the matrix dissolved once water penetrated the matrix and were then able to diffuse to the surface through pores created as the particles of molecules dissolved. Scanning electron microscopy showed that the pores were interconnected (7). 

An even more refined method of study is interference-contrast microscopy [following Nomarski (767)] which converts minute topographical differences into color changes. Replica electron microscopy (77), gold decoration (see Section III,A,1), and scanning electron microscopy are also useful but less practicable. Occasionally it is profitable to follow the course of the reaction, in situ, using time-lapse cinematography (77). 

Figure 8.59 Optical micrograph showing the transformation zone around a crack in a partially stabilized zirconia. Nomarski interference is used to provide the contrast which is caused by the surface uplift of the transformed material. (From D. B. Marshall et al., 1990, reproduced courtesy of The American Ceramic Society, Westerville, OH.)...

Another system for examination of low-contrast objects such as living cells is the Nomarski or differential interference contrast system. It is also particularly useful for materials that cannot be stained satisfactorily for other reasons, such as very thin sections that take up too little stain. This system employs polarizing filters and quartz prisms instead of the annular diaphragm and phase plates used in phase contrast. This eliminates the halo effect seen in phase contrast, rendering sharply defined images with good contrast, having a characteristically (pseudo) three-dimensional appearance. It is rather less suited to routine work than phase contrast however, and is considerably more expensive. 

The Nomarski differential interference contrast technique accentuates changes in specimen thickness and refractive index in transmission without giving the haloes round fine features that distract from the usefulness of the phase-contrast technique. In reflection, images are obtained that strongly accentuate the topographical features present. 

Nomarski microscopy Differential interference contrast microscopy utilizes differences in refractive index to visuahze structures producing a nearly three-dimensional image. 

Patches are normally obtained under an inverted microscope. The magnification will depend on the size of the cells that are going to be studied. Illumination is phase contrast or differential interference contrast (Nomarski) in order to have a clear image of cells, taking into account that they are living cells without any dye. The illumination power supply of the microscope has to be localized far from the set-up, especially when it is an a.c. power supply. 

Nomarski Differential Interference Contrast (DIC). In 1955 the physicist George Nomarski simplified the two-beam interference microscope in a way that it became available for routine microscopy [11 (Fig, 6), DIC uses modified Wollaston prisms (Fig. 6B). lying outside the focal... 

W. Lang Nomarski Differential Interference Contrast Microscopy. Zeiss Inf. 16 (1968) no. 70, 114-120. 

However, the most widely used type of interference microscopy is that giving Differential Interference Contrast (DIC), widely known as Nomarski contrast. 

Another technique for crystallinity analysis is the measurement of pole figures. It is widely applied for thin films, LPE films, melt-processed polycrystalline samples with a noticeable texture (Goyal et al. 1993). In fig. 33, a good crystallinity of the Y123 LPE film is evidently obtained due to a specific growth mechanism, mentioned above (sect. 5.4), despite the large misfit between the film and the MgO substrate. Differential interference contrast (DIM or Nomarski) microscopy can be successfully applied to observe misorientation on flat ( mirror-like ) surfaces (Klemenz and Scheel 1993). 

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