title: Lithium ion diffusion measurements on a garnet-type solid conductor Li6.6La3Zr1.6Ta0.4O12 by using a pulsed-gradient spin-echo NMR method.
abstract: The garnet-type solid conductor Li7-xLa3Zr2-xTaxO12 is known to have high ionic conductivity. We synthesized a series of compositions of this conductor and found that cubic Li6.6La3Zr1.6Ta0.4O12 (LLZO-Ta) has a high ionic conductivity of 3.7×10(-4)Scm(-1) at room temperature. The (7)Li NMR spectrum of LLZO-Ta was composed of narrow and broad components, and the linewidth of the narrow component varied from 0.69kHz (300K) to 0.32kHz (400K). We carried out lithium ion diffusion measurements using pulsed-field spin-echo (PGSE) NMR spectroscopy and found that echo signals were observed at T≥313K with reasonable sensitivity. The lithium diffusion behavior was measured by varying the observation time and pulsed-field gradient (PFG) strength between 313 and 384K. We found that lithium diffusion depended significantly on the observation time and strength of the PFG, which is quite different from lithium ion diffusion in liquids. It was shown that lithium ion migration in the solid conductor was distributed widely in both time and space.
authors.affiliation: Institute of Applied Physics, University of Tsukuba, Tsukuba 305-8573, Japan. Electronic address: hayamizu.k3@gmail.com.
authors.forename: Kikuko
authors.initials: K
authors.lastname: Hayamizu
authors.affiliation: Department of Chemistry for Materials, Mie-University, Tsu, Mie 514-8507, Japan.
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Matsuda
authors.affiliation: Department of Chemistry for Materials, Mie-University, Tsu, Mie 514-8507, Japan; Japan Science and Technology Agency, PRESTO, Honcho, Kawaguchi 332-0012, JAPAN.
authors.forename: Masaki
authors.initials: M
authors.lastname: Matsui
authors.affiliation: Department of Chemistry for Materials, Mie-University, Tsu, Mie 514-8507, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Imanishi
keywords: (7)Li NMR; Garnet-type tantalum-doped conductor; Li(6.6)La(3)Zr(1.6)Ta(0.4)O(12); Lithium ion diffusion; Pulsed-gradient spin-echo (PGSE) NMR