High Schottky barrier at grain boundaries observed in Na1/2Sm1/2Cu3Ti4O12 ceramics

- NSCTO exhibits a high ɛ′ of 7.0-8.4 × 103 and low tan δ of 0.030-0.041.
- NSCTO exhibits a high Eb of ∼2208 V cm−1 and large α of 15.6.
- Giant ɛ′ response is attributed to the electrically heterogeneous microstructure.
- High Φb values at grain boundaries are found to be 0.925-0.964 eV.
- Formation of a potential barrier at grain boundaries is caused by Schottky effect.