3-BaTiO3體系的準(zhǔn)同型相界通常位于0.70BiFeO3-0.30BaTiO3組分附近。然而，對于BiFeO3-BaTiO3體系，BaTiO3含量越高其居里溫度越低。因此，在較低的BaTiO3含量組分附近構(gòu)建準(zhǔn)同型相界是使其同時獲得良好的壓電活性和高居里溫度的有效策略。采用固相法制備了0.74BiFe1-xGaxO3-0.26BaTiO3（x=0~0.05）系列無鉛壓電陶瓷，研究了Ga含量對其物相結(jié)構(gòu)與電性能的影響。結(jié)果表明：隨著Ga含量的增加，陶瓷樣品從三方相逐漸向贗立方相轉(zhuǎn)變。當(dāng)x≤0.01，陶瓷樣品為三方相結(jié)構(gòu)；而當(dāng)0.04≤x≤0.05，陶瓷樣品為贗立方結(jié)構(gòu)，在0.02≤x≤0.03形成了準(zhǔn)同型相界（三方-贗立方）。另外，由于容忍因子的升高，該系列陶瓷的居里溫度隨著Ga含量的增加而略有降低。位于準(zhǔn)同型附近的陶瓷樣品表現(xiàn)出良好的壓電活性和較高的居里溫度。;Morphotropic phase boundary (MPB) is very important for enhancing piezoelectric properties of piezoceramics. In general, the MPB of BiFeO3-BaTiO3 system ceramics locates near the composition of 0.70BiFeO3-0.30BaTiO3. However, higher content of BaTiO3 will lead to lower Curie temperature of BiFeO3-BaTiO3 ceramics. Therefore, constructing an MPB for BiFeO3-BaTiO3 ceramics with lower BaTiO3 content is a reasonable strategy to obtain both the good piezoelectric property and high Curie temperature. 0.74BiFe1-xGaxO3-0.26BaTiO3 (x=0~0.05) lead-free piezoceramics were fabricated by traditional sintering methods, and effect of Ga content on the structures and electrical performances was investigated. Results show that a composition-driven phase transition from rhombohedral (R) to pseudocubic (pC) is identified as x increases from 0 to 0.05. The ceramics show symmetries of R at x≤0.01 and pC at 0.04≤x≤0.05, and the MPB with R-pC coexistence is detected in the composition range of 0.02≤x≤0.03. The Curie temperature of the piezoceramics decreases slightly owing to increased tolerance factor t with the increment of Ga content. In particular, the high Curie temperature ~515 °C and improved piezoelectric property of piezoelectric coefficient d33 of ~127 pC/N are obtained in the ceramics near MPB."/>
3-BaTiO3;無鉛;piezoelectric materials;electrical performances;phase transition;BiFeO3-BaTiO3;lead-free"/>