Accession Number : AD0770315

Title :   NMR Relaxation Studies of Ferroelectric Colemanite,


Personal Author(s) : Watton,A. ; Petch,H. E. ; Pintar,M. M.

Report Date : 02 JAN 1973

Pagination or Media Count : 9

Abstract : Proton spin-lattice relaxation of the Zeeman reservoir in the laboratory and rotating frames and of the dipolar reservoir have been studied in ferroelectric colemanite. These studies indicate the presence of two relaxation mechanisms which can be related to motions of the water molecules. The first, referred to as the flip mode and identified with 180 degree flips of the water molecules about their H-O-H bisectrices, is characterized by a correlation time and U-shaped relaxation minimum expected for a normal thermally activated process. The second, referred to as the jump mode and associated with a structural configuration change, produces a cusp-shaped dip in the relaxation over a very small temperature range in the vicinity of the phase transition. (Modified author abstract)

Descriptors :   *Ferroelectric materials, *Nuclear magnetic resonance, Borates, Molecular structure, Water, Ferroelectricity, Phase transformations, Low temperature, Canada

Subject Categories : Geology, Geochemistry and Mineralogy
      Atomic and Molecular Physics and Spectroscopy
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE