Optical microscopy, diamond

Ammonium dinitramide and dinitro azetidinium dinitramide For both of these materials the pressure/temperature and reaction phase diagram have been determined using a high-temperature-high-pressure diamond anvil cell with FTIR spectroscopy, Raman spectroscopy and optical microscopy. For ammoninm dinitramide energy dispersive X-ray diffraction was also employed (Russell et al. 1996, 1997). 

Optical microscopy of specimens from tensile tests shows significant differences in deformation behavior. The 2L, 3LA, 3LAI, 3LE, and 4L materials develop diffuse shear bands and stress-whiten at, and beyond, the yield point. The 3LB and 3LD materials stress-whiten with coarse shear bands emanating from diamond-shaped features that form just prior to yield they also develop an undulating surface texture. The 3LC materials show similar coarse shear bands emanating from diamond-shaped features and have surface texture, but they stress-whiten only faintly. Examples of the different types of shear banding are shown in Figure 5. 

We have made direct optical observations and measmements of microbial activity at various pressures. As in the above experiments, we have used diamond anvil cells in combination with micro-Raman spectroscopy and optical microscopy to directly monitor their viability and metabolic activity at extreme conditions [58]. The following is an overview of these direct observations of microbial activity under extreme pressures and their implications for adaptive mechanisms of life (as we know it) on this planet. 

In situ optical microscopy observation of the indentation process demonstrated that diamond becomes nontransparent to visible light in the loaded zone [196] (Fig. 40 white regions show the reflection of light). This is consistent with a narrowing optical window in a diamond anvil that was observed at much higher... 

The hardness of GST is only 2.3—2.4 GPa [5], while the hardness values of A1 and Cu are 0.5—1.2 and 3.0 GPa, respectively. So GST is a relatively soft material. Hence, it can be easily scratched during CMP by hard materials like the pad, agglomerated large silica particles, diamond particles from conditioner, and so on. Figure 19.2 shows a typical optical microscopy (OM) image of a post-CMP GST surface polished using... 

Hardness measures the plastic resistance of a surface to contact loading, that is, its resistance to permanent deformation. Most experiments are carried out using a Vickers diamond pyramid. When a Vickers diamond (four-sided) pyramid is loaded over the plastic threshold, one can determine, after the test, the mean pressure or hardness FI defined by the ratio between the applied load and the projected surface Ap of the permanent deformation left by the indenter. This area can be determined from the mark diagonals (Ap = 2a, a half the mean size of the diagonal Figure 8.10) observed under elevated loads by means of optical microscopy. Hardness is... 

Synthetic diamonds have been grown at pressures of around 5.5 GPa and 1527°C from a C-Co-Fe alloy melt by [1990Pav]. EXAFS, XRD, SEM and optical microscopy revealed metallic inclusions in the diamond, consisting of a mixture of (Fei tCO t)3C and ledeburite eutectic. 

Ruh] EXAFS, XRD, SEM, optical microscopy Inclusions in synthetic diamonds... 

As mentioned earlier, CL is a powerful tool for the characterization of optical properties of wide band-gap materials, such as diamond, for which optical excitation sources are not readily available. In addition, electron-beam excitation of solids may produce much greater carrier generation rates than typical optical excitation. In such cases, CL microscopy and spectroscopy are valuable methods in identifying various impurities, defects, and their complexes, and in providing a powerful means for the analysis of their distribution, with spatial resolution on the order of 1 pm and less. ... 

A.H. Deutchman and R.J. Partyka (Beam Alloy Corporation observe, "Characterization and classification of thin diamond films depend both on advanced surface-analysis techniques capable of analyzing elemental composition and microstructure (morphology and crystallinity), and on measurement of macroscopic mechanical, electrical, optical and thermal properties. Because diamond films are very thin (I to 2 micrometers or less) and grain and crystal sizes are very small, scanning electron microscopy... 

The microstructures of the consolidated and deformed samples were characterized by X-ray diffraction, optical and electron microscopy (SEM and TEM). The samples for mechanical testing have been prepared by spark erosion. The linear thermal expansion was determined by using a thermomechanical system (TMA). The temperature-dependent elastic moduli have been measured by the resonance frequency and the pulse-echo method. The bulk moduli were determined by synchrotron radiation diffraction using a high-pressure diamond-die cell at HASYLAB. The compression and creep tests were performed with computer-controlled tensile testing and creep machines. 

Structural Studies. Structural characteristics of both natural and synthetic diamonds have been studied using electron microscopy and i.r. and optical absorption spectroscopy. — Greatest interest is associated with defect structures of electron-irradiated diamond. ... 

Optical and Electron Microscopy. Samples of film for optical and electron microscopy were prepared by microtoming. The samples for optical phase contrast microscopy were approximately 15-20jU thick whereas those for electron microscopy were ultra microtomed with a diamond knife to about 0.05-0. lju, thickness. A Leitz Ortholux microscope was used for the phase contrast microscopy and an RCA-EMU-36 electron microscope at 40,000 X magnification was used for the electron microscopy. 

The octahedral pressure cells containing the samples were recovered from the multi-anvil experiment and either broken or cut in half, using a diamond wiresaw. In the latter case, the j -sialon samples were also halved in the axial direction. The specimens were then characterized with optical and scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron probe microanalysis (EPMA), powder X-ray diffractometry (XRD), and microhardness testing using the Vickers method. 

Figure 7 Extreme examples of presses for preparing from solids films suifable for mid-infrared examinafion (A) hand-operafed, hydraulic, heafed, molding press for preparing fhin films from polymer samples for macro mid-infrared examinafions (B) diamond anvil minicell for solid sample compression and confainmenf, particularly for FT-IR microscopy sfudies and (C) schemafic of diamond anvil minicell. (A) Reproduced by kind permission of George E. Moore Son Lfd., Birmingham, Wesf Midlands, UK. (B and C) Reproduced by kind permission of High Pressure Diamond Optics, Inc., Tucson, AZ, USA.)...

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