The high-Curie temperature (T_C) 0.15Pb(Mg_1/3Nb_2/3)O₃-0.38PbHfO₃-0.47PbTiO₃ (PMN-PH-PT) piezoelectric ceramics were prepared by the partial oxalate route via the B-site oxide mixing method. The obtained uniform nm-sized PMN-PH-PT precursor powders provide high calcining and sintering activity for synthesizing ceramics, based on which the synthesis conditions were tailored as calcining at 775 °C and sintering at 1245 °C. The partial oxalate route synthesized PMN-PH-PT ceramics are far superior to the counterparts synthesized by the columbite precursor method and exhibit excellent thermal stability of the piezoelectric properties under T_C (∼292 °C), ensuring the potential application in transducers under elevated environmental temperatures. The temperature dependent Raman spectroscopy not only proves the occurrence of the ferroelectric to paraelectric phase transition around T_C, but also confirms the successive phase symmetry transitions, which correlate with the polar nanoregions (PNRs) and/or the coexistence of multiple ferroelectric phases, revealing the origin of the enhanced electrical properties in the PMN-PH-PT ceramics.

通过部分草酸盐途径通过B制备高居里温度（T _C）0.15Pb（Mg _1/3 Nb _2/3）O ₃ -0.38PbHfO ₃ -0.47PbTiO ₃（PMN-PH-PT）压电陶瓷现场氧化物混合法。所获得的均匀纳米尺寸的PMN-PH-PT前体粉末为合成陶瓷提供了高煅烧和烧结活性，在此基础上，将合成条件调整为在775°C下煅烧和1245°C烧结。草酸路线合成的PMN-PH-PT陶瓷远远优于钴矿前驱体方法合成的陶瓷，并且在T _C下表现出优异的压电性能热稳定性。（〜292°C），确保在高温环境下在换能器中的潜在应用。温度相关的拉曼光谱不仅证明了在T _C附近铁电至顺电相变的发生，而且证实了连续的相对称跃迁，与极性纳米区域（PNR）和/或多个铁电相的共存相关，揭示了PMN-PH-PT陶瓷增强电性能的起源。