2019 Volume 127 Issue 8 Pages 521-526
Single-crystal rods of Li7−xLa3Zr2−xTaxO12 (X = 0.2, 0.4, 0.5, 0.6, 0.8) were grown by floating zone melting. The typical size of the single-crystal rod was 8 mm in diameter and 70 mm in length. Li7−xLa3Zr2−xTaxO12 (X = 0.2, 0.4, 0.5, 0.6, 0.8) crystallizes in a cubic structure with an Ia-3d space group. Single crystal structure analysis was performed for all single crystals. How the lithium ion conductivity varies with the substitution amount of tantalum was investigated using a single crystal. Analyzing the results of AC impedance measurements, we estimated the total Li-ion conductivity of member in Li7−xLa3Zr2−xTaxO12 single-crystal. As a result, when X = 0.4, the lithium ion conductivity became the maximum, and it was 1.10 × 10 −3 S cm−1 at 298 K. The activation energy ticked up with increasing tantalum substitution.