Two-dimensional nutation echo 75As NQR spectroscopy in antiferroelectric NH4H2AsO4 using the maximum entropy method
✍ Scribed by P. Kątowski; M. Maćkowiak
- Publisher
- John Wiley and Sons
- Year
- 1995
- Tongue
- English
- Weight
- 337 KB
- Volume
- 33
- Category
- Article
- ISSN
- 0749-1581
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✦ Synopsis
Abstract
With a view to developing efficient methodologies for the evaluation of the asymmetry parameter of the electric field gradient (EFG) tensor from polycrystalline specimens, an alternative approach which involves two‐dimensional spin‐echo NQR data processing by the maximum entropy method (MEM) is presented. The superiority of MEM over the traditional fast Fourier transform (FFT) method is demonstrated by the analysis of two‐dimensional NQR data obtained using the modified pulse sequence. The method has been successfully applied to the determination of the EFG tensor at the ^75^As site in the antiferroelectric phase of polycrystalline ammonium dihydrogenarsenate (ADA), where conventional nutation spectroscopy fails owing to the large NQR linewidth.