cm7b04117_si_001.cif (2 kB)
Electrostatic Interactions versus Second Order Jahn–Teller Distortion as the Source of Structural Diversity in Li3MO4 Compounds (M = Ru, Nb, Sb and Ta)
dataset
posted on 2017-12-07, 00:00 authored by Quentin Jacquet, Gwenaëlle Rousse, Antonella Iadecola, Matthieu Saubanère, Marie-Liesse Doublet, Jean-Marie TarasconWith
the advent of layered rocksalt oxides showing anionic redox
activity toward Li, there has been an increased focus on designing
new rocksalt structures and, more particularly, compounds pertaining
to the Li3MO4 family. The structural richness
of this family is nested in its ability to host many different cations,
leading to the formation of superstructure patterns whose predictability
is still limited. Thus, there is a need to understand the formation
of such superstructures, as cationic arrangements have a crucial effect
on their physical properties. Herein we propose a combined experimental
and theoretical approach to understand the interactions governing
cation ordering in binary systems of general composition given by
Li3MyM′1–yO4 (M and M′ being Ru, Nb, Sb,
and Ta). Through complementary X-ray diffraction and X-ray absorption
spectroscopy techniques, we reveal a solid-solution behavior for the
Li3RuySb1–yO4 system, as opposed to Li3SbyNb1–yO4 that enlists four rocksalt structures with different
cation orderings. We use DFT calculations to rationalize such a structural
diversity and find that it is controlled by a delicate balance between
electrostatic interactions and charge transfer due to a second order
Jahn–Teller distortion. This insight provides a new viewpoint
for understanding cationic arrangements in rocksalt structures and
guidelines to design novel phases for applications such as Li-ion
batteries or ionic conductors.