A single crystal X-ray and powder neutron diffraction study on NASICON-type Li 1+x Al x Ti 2−x (PO 4 ) 3 (0 ≤ x ≤ 0.5) crystals: Implications on ionic conductivity

Abstract Single crystals of NASICON-type material Li 1+x Ti 2−x Al x (PO 4 ) 3 (LATP) with 0 ≤ x ≤ 0.5 were successfully grown using long-term sintering techniques. Sample material was studied by chemical analysis, single crystal X-ray and neutron diffraction. The Ti 4+ replacement scales very well with the Al 3+ and Li + incorporation. The additional Li + thereby enters the M3 cavity of the NASICON framework at x, y, z ∼ (0.07, 0.34, 0.09) and is regarded to be responsible for the enhanced Li + conduction of LATP as compared to Al-free LTP. Variations in structural parameters, associated with the Ti 4+ substitution with Al 3+  + Li + will be discussed in detail in this paper.