Lithium ion conductivity of A-site deficient perovskite solid solutions

Over twenty of A-site deficient perovskite solid solution with Li+ ion conductivity (Li-ADPESSs) were prepared with the M and Li concentration fixed at M0.56Li0.33TiO3 in the five series: (A) (La1−XNdX)0.56Li0.33TiO3, (B) La0.56Li0.33M(IV)XTi1−XO3[M(IV)=Zr,Hf], (C) (Ca1−XSrX)0.56Li0.33Ta0.56Ti0.44O3, (D) (Ca1−XSrX)0.56Li0.33Fe0.225 Ta0.775O3, E) Sr0.56Li0.33M()0.225Ta0.775O3[M()=Cr,Fe,Co,Ga,Y]. Except for the few, the quenched samples were the α-form with disordered arrangement of the A-site ions. The relation between bulk conductivity (σb) and the cube root (V1/3) of the perovskite cell volume showed a maximum at V1/3≈387 pm for the series A, B and at V1/3≈395 pm for the series C–E, respectively. The perovskite framework containing less covalent, large cations calls for a larger optimal cell volume for fast conduction.