Description:
The electrical properties and phase transition behavior of 0.95(K 0.49 Na 0.49 Li 0.02 )(Ta 0.2 Nb 0.8 )O 3 -0.05BaZrO 3 with 2 wt% MnO 2 addition (KNNLT-BZM) lead-free epitaxial ferroelectric films on LaNiO 3 (LNO)-coated SrTiO 3 (STO) (001) substrate are investigated. An orthorhombic and tetragonal mixed phase is recorded in our sample, and the chemical doping of MnO 2 results demonstrate that the Mn 2+ /Mn 3+ coexistence suppresses the leakage current, greatly improving the electrical performance featured by a lower leakage value of 8×10 -11 A/cm 2 , a twice remnant polarization of 44.7 μC/cm 2 , and excellent P-E loops at a wide frequency range from 50 Hz to 10 kHz. Temperature-dependent dielectric property and XRD measurements demonstrate that the mixed phase transformed to tetragonal phase at a temperature of 300 °C and the film obtains a high Curie temperature above 440 °C. Meanwhile, stable hysteresis loops can be measured from room temperature to 200 °C. The observed electrical property and thermal stability of KNNLT-BZM films promote the potential applications of KNN-based lead-free materials in microelectronic devices