Dipolar oscillations and phase interferometry in solid state n.m.r

1981 ◽  
Vol 299 (1452) ◽  
pp. 565-584 ◽  
Keyword(s):  
Solid State ◽  
High Resolution ◽  
General Theory ◽  
Double Resonance ◽  
Experimental Techniques ◽  
Difference Spectra ◽  
Catalytic Systems ◽  
Na Ions ◽  
Hydrogen Bonded Systems ◽  
Dipolar Modulation

Dipolar modulation and phase interferometry, which are part of the class of high-resolution, double-resonance n.m.r. experimental techniques used to study solids, are examined in detail. A general theory of double-resonance interactions based on the heteronuclear dipolar Hamiltonian is presented. A number of experiments dealing with both heteronuclear and homonuclear dipolar modulation and selective dipolar difference spectra are discussed. These experiments are used to study hydrogen-bonded systems and catalytic systems. A simple theory explaining phase interferometry in n.m.r. is presented. Several phase interferometric experiments are also discussed. The motion and structure of 23 Na ions in β-alumina are examined with the use of this technique.

The Distortion Moment Microwave Spectrum of 12CH4 in the Ground Vibronic State

1975 ◽  
Vol 53 (19) ◽  
pp. 1791-1805 ◽  
Author(s):  
C. W. Holt ◽  
M. C. L. Gerry ◽  
I. Ozier
Keyword(s):  
High Resolution ◽  
Least Squares ◽  
Double Resonance ◽  
Microwave Spectrum ◽  
Experimental Techniques ◽  
Rotational Spectrum ◽  
Vibronic State ◽  
Microwave Spectrometer ◽  
The One ◽  
Theoretical Considerations

Seven Q branch transitions between 7.8 and 20 GHz have been observed in the distortion moment pure rotational spectrum of 12CH4 in its ground vibronic state. The spectrum was obtained using a conventional Stark modulated microwave spectrometer specially modified for the detection of very weak lines. From the frequencies of these seven transitions, along with the ortho–para splitting known for the (J = 2) state and two Q branch splittings measured earlier by infrared–microwave double resonance, we have determined the one quartic tensor distortion constant DT, the two sextic constants H4T and H6T, and the three octic constants L4T, L6T, and L8T. These are (in Hz): DT = (132 943.41 ± 0.71); H4T = −(16.9839 ± 0.0076); H6T = (11.0342 ± 0.0086); L4T = (20.27 ± 0.24) × 10−4; L6T = −(26.77 ± 0.35) × 10−4; L8T = −(30.0 ± 1.8) × 10−4. The errors are the standard deviations resulting from a least squares analysis. Estimates are also given of the absolute errors. These results consitute the first measurement of the octic distortion constants. The values for DT, H4T, and H6T are compared to earlier determinations. The theoretical considerations that affect the observation of these transitions are reviewed and a detailed description of the special experimental techniques used is given. The method of analysis is described. Finally, as an aid to other high resolution studies of methane and to possible astrophysical detection of the molecule, the Q branch splittings are tabulated up to J = 21.

Multinuclear Solid-State High-Resolution and13C -{27Al} Double-Resonance Magic-Angle Spinning NMR Studies on Aluminum Alkoxides

2006 ◽  
Vol 110 (13) ◽  
pp. 6553-6560 ◽  
Author(s):  
Anuji Abraham ◽  
Roel Prins ◽  
Jeroen A. van Bokhoven ◽  
Ernst R. H. van Eck ◽  
Arno P. M. Kentgens
Keyword(s):  
Solid State ◽  
High Resolution ◽  
Double Resonance ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Nmr Studies ◽  
Angle Spinning

The use of high-resolution FESEM to study solid-state phase transformations and reactions

1994 ◽  
Vol 52 ◽  
pp. 1028-1029
Author(s):  
P. G. Kotula ◽  
D. D. Erickson ◽  
C. B. Carter
Keyword(s):  
Solid State ◽  
High Resolution ◽  
Phase Transformations ◽  
High Efficiency ◽  
Sol Gel ◽  
Quantitative Information ◽  
Solid State Reactions ◽  
Critical Dimensions ◽  
Backscattered Electrons ◽  
Backscattered Electron

High-resolution field-emission-gun scanning electron microscopy (FESEM) has recently emerged as an extremely powerful method for characterizing the micro- or nanostructure of materials. The development of high efficiency backscattered-electron detectors has increased the resolution attainable with backscattered-electrons to almost that attainable with secondary-electrons. This increased resolution allows backscattered-electron imaging to be utilized to study materials once possible only by TEM. In addition to providing quantitative information, such as critical dimensions, SEM is more statistically representative. That is, the amount of material that can be sampled with SEM for a given measurement is many orders of magnitude greater than that with TEM.In the present work, a Hitachi S-900 FESEM (operating at 5kV) equipped with a high-resolution backscattered electron detector, has been used to study the α-Fe2O3 enhanced or seeded solid-state phase transformations of sol-gel alumina and solid-state reactions in the NiO/α-Al2O3 system. In both cases, a thin-film cross-section approach has been developed to facilitate the investigation. Specifically, the FESEM allows transformed- or reaction-layer thicknesses along interfaces that are millimeters in length to be measured with a resolution of better than 10nm.

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