Lattice Dynamics in the NASICON NaZr2(PO4)3 Solid Electrolyte from Temperature-Dependent Neutron Diffraction, NMR, and Ab Initio Computational Studies

Published

May 10, 2022

Author(s)

Emily Morgan, Hayden Evans, Kartik Pilar, Craig Brown, Raphaele Clement, Ryo Maezono, Ram Seshadri, Bartomeu Monserrat, Anthony Cheetham

Abstract

Natrium super ionic conductor (NASICON) compounds form a rich and highly chemically-tunable family of crystalline materials that are of widespread interest because they include exemplars with high ionic conductivity, low thermal expansion, and redox tunability. This makes them suitable candidates for applications ranging from solid-state batteries to nuclear waste storage materials. The key to an understanding of these properties, including the origins of effective cation transport and low, anisotropic (and sometimes negative) thermal expansion, lies in the lattice dynamics associated with specific details of the crystal structure. Here, we closely examine the prototypical NASICON compound, NaZr₂(PO₄)₃, and obtain detailed insights into such behavior via variable-temperature neutron diffraction and ²³Na and ³¹P solid-state NMR studies, coupled with comprehensive density functional theory-based calculations of NMR parameters. Temperature-dependent NMR studies yield some surprising trends in the chemical shifts and the quadrupolar coupling constants that are not captured by computation unless the underlying vibrational modes of the crystal are explicitly taken into account. The work presented here widens the utility of NMR crystallography to include thermal effects as a unique probe of interesting lattice dynamics in functional materials.

Citation

Chemistry of Materials

Volume

34

Issue

9

Pub Type

Journals

Keywords

Ion Conductor, NASICON, Nuclear Magnetic Resonance, Neutron Diffraction

Citation

Morgan, E. , Evans, H. , Pilar, K. , Brown, C. , Clement, R. , Maezono, R. , Seshadri, R. , Monserrat, B. and Cheetham, A. (2022), Lattice Dynamics in the NASICON NaZr₂(PO₄)₃ Solid Electrolyte from Temperature-Dependent Neutron Diffraction, NMR, and Ab Initio Computational Studies, Chemistry of Materials (Accessed March 13, 2025)