High resolution solid state silicon

NMR measurements The high resolution, solid state NMR measurements were performed at 30 C on a JEOL JNM 400 spectrometer. Sample membranes were cut into small pieces having an area of about 5x5 mm and packed into each sample tube, llie spin lattice relaxation time (T ) of carbons and silicon were obtained by the CPT, pulse sequence, operating at a spinning speed of 6 kHz. 

Freitas, J.C.C., Emmerich, F.G., and Bonagamba, T.J. High-resolution solid-state NMR study of the occurrence and thermal transformations of silicon-containing species in biomass materials. Chem.. Mater. 2000 12 711-718. 

In conclusion, although all aluminium (and silicon) atoms in zeolite Y crystals are equally accessible through the zeolite cavities, they are chemically not identical, and their reactivity towards dealumination reagents could be different. Unfortunately, no methods are actually available for determining directly the T atom environment in terms of NNN of an aluminium atom. Indeed, the different aluminium T sites are even not resolved in the 27 1 resonance envelope, measured with the high-resolution solid state magic angle... 

Solid-state detectors based on silicon- or germanium-diodes possess better resolution than gas counters, particularly when cooled with liquid nitrogen, but they allow only very low count rates. PIN diodes have also recently become available and have been developed for the instruments used in the examination of Martian soils (Sects. 3.3 and 8.3). A very recent development is the so-called silicon-drift detector (SDD), which has very high energy resolution (up to ca. 130 eV) and large sensitive detection area (up to ca. 1 cm ). The SNR is improved by an order of magnitude compared to Si-PIN detectors. Silicon drift detectors may also be used in X-ray florescence spectroscopy, even in direct combination with Mossbauer spectroscopy (see Sects. 3.3 and 8.3). 

W. Moritz, T. Yoshinobu, F. Finger, S. Krause, M. Martin-Fernandez and M.J. Schoning, High resolution LAPS using amorphous silicon as the semiconductor material, Sens. Actuators B Chem., 103 (2004) 436—441. J.C. van den Heuvel, R.C. van Oort and M.J. Geerts, Diffusion length measurements of thin amorphous silicon layers, Solid State Commun., 69(8) (1989) 807-810. 

Magi, M., E. Lippmaa, A. Samoson, G. Engelhardt, and A. R. Grimmer (1984). Solid-state high resolution silicon-29 chemical shifts in silicates. J. Phys. Chem. 88, 1518-22. 

Chamard V, Pichat C, Dolino G (2001) Rinsing and drying studies of porous silicon by high resolution X-ray diffraction. Solid State Commun 118(3) 135-139... 

High-resolution Si NMR spectra of solids can be obtained using H- Si CPMAS, as demonstrated by Lippmaa et al. in 1981. Si NMR spectroscopy, originally applied to study silicate solutions and silicon-organic compounds in the liquid phase, has since evolved into an important tool for the investigation of various classes of crystalline and amorphous solids. Klinowski and co-workers provided remarkable new insights into the structure and catalytic activity of diverse aluminosilicates employing H, Si, Al and MAS NMR, as well as an array of two dimensional solid state NMR methods. ... 

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