Advances in modification of contradictory relationship: Simultaneously realizing large piezoelectricity and high Curie temperature in potassium sodium niobate based ferroelectrics
For potassium sodium niobate (KNN) based ferroelectrics, a critical contradictory relationship is that their higher their piezoelectricity is often achieved at the cost of sacrificing their Curie temperature, which severely restricts this promising materials practical process. How to modify the contradictory relationship between them is one of the urgent aims in high temperature applications. Here, a new material system of 0.965K0.54Na0.46Nb1-xSbxO3-0.03Bi0.5Na0.5ZrO3-0.005BiFeO3 (KNNSx-BNZ-BF, 0 ≤ x ≤ 0.03) has been obtained by the compositional materials selection, and a considerable progress on simultaneously realizing large d33 (~505 pC/N) and high Tc (~ 285 oC) is made in this ferroelectrics, which is superior to the previously reported results to date in KNN-based ferroelectrics. In addition, a good temperature-independent of strain properties is also attained in this materials due to the high Tc. Therefore, such a KNN-based system may promote the practical process of lead-free materials in high temperature fields.