Lead-207 NMR spectroscopic study of lead-based electronic materials and related lead oxides
Static and MAS {sup 207}Pb NMR spectra of a series of lead oxides, including the electronic materials PbTiO{sub 3} (PT), PbZrO{sub 3}, Pb(Zr{sub 0.53}Ti{sub 0.47})O{sub 3}, Pb(Mg{sub 0.33}Nb{sub 0.67})O{sub 3} (PMN), and 0.66PMN/0.34PT, have been measured. The chemical shift parameters ({delta}{sub iso}, {delta}{sub aniso}, and {eta}) and the spin-lattice relaxation times have been determined for most of these compounds. The symmetry of the local environment of the lead(II) site and the covalency of the Pb-O bonds are determined to be the best indicators of the {sup 207}Pb chemical shift parameters. Ionic compounds (e.g., PbSO{sub 4} and Pb(NO{sub 3}){sub 2}) have isotopic chemical shifts from {minus}3,600 to {minus}2,500 ppm and small absolute anisotropic chemical shifts (<500 ppm); while covalent lead oxides (e.g., PbO and Pb{sub 3}O{sub 4}) have isotropic chemical shifts from 800 to 1,900 ppm and large absolute anisotropic chemical shifts (1,900 to 2,600 ppm). PbTiO{sub 3} and PbZrO{sub 3} have intermediate isotropic ({minus}1,419 to {minus}1,017 ppm) and anisotropic chemical shifts ({minus}838 to {minus}546 ppm) consistent with an intermediate degree of covalent bonding. Pb(Zr{sub 0.53}Ti{sub o.47})O{sub 3}, PMN, and 0.66PMN/0.34PT have single broad asymmetric {sup 207}Pb NMR resonances, with chemical shifts and line widths consistent with Pb-O bonds that are less covalent than those in PbO and more covalent than those in PbTiO{sub 3} and PbZrO{sub 3}. For the {sup 207}Pb NMR spectra of Pb(Zr{sub 0.53}Ti{sub 0.47})O{sub 3}, PMN, and 0.66PMN/0.34PT, chemical shift dispersion is a significant contribution to the line width, consistent with the presence of a range of inequivalent lead(II) sites in these disordered perovskite materials.
- Research Organization:
- South Dakota State Univ., Brookings, SD (US)
- OSTI ID:
- 20013091
- Journal Information:
- Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical, Vol. 103, Issue 48; Other Information: PBD: 2 Dec 1999; ISSN 1089-5647
- Country of Publication:
- United States
- Language:
- English
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