Solid State Multinuclear NMR Studies of Relaxor Ferroelectrics
Abstract
Multinuclear (207Pb, 45Sc, 93Nb) NMR has been used to investigate the local structure and cation disorder in solid solutions of (1-x) Pb(Mg1/3Nb2/3)O3: x Pb(Sc1/2Nb1/2)O3, as a function of concentration. The relaxor ferroelectrics have been well characterized by X-ray and dielectric response measurements(1). MAS, and 3QMAS spectra are presented for 93Nb at 14.0 and 19.6 Tesla. The 93Nb MAS lineshapes have been assigned to species with different arrangements of the nearest B-cation neighbors. It is necessary to include distributions of the electric field gradient parameters and dispersions in isotropic chemical shifts; these have been estimated from the data. The relative intensities of each spectral component are analyzed and the data strongly supports the modified Random Site model. To explain NMR intensities and to validate the model, Monte Carlo simulations will be presented. (1) P. K., Davies, L. Farber, M. Valant, and M. A. Akabas, AIP Conf. Proc. 535 (2000) 38-46.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2002
- Bibcode:
- 2002APS..MARQ20010H