Relaxor ferroelectric transition and energy storage enhancement in BaTiO3 ceramics through high-energy ball milling

This study demonstrates a simple and cost-effective route to induce relaxor ferroelectric behavior in BaTiO3 (BTO) ceramics. Sintered pellets prepared from unmilled and milled BTO powders were characterized using Xray diffraction (XRD), dielectric spectroscopy, and P–E measurements. XRD confirmed the retention of the tetragonal P4mm phase in all samples. Dielectric spectra showed a clear evolution from a sharp Curie peak (~120 ◦C) in pellets obtained from unmilled powders to a broad diffuse transition (60 ◦C–180 ◦C) after milling; with the diffuseness coefficients increasing from 0.52 to 1.30. Piezoresponse force microscopy corroborated the formation of polar nanoregions in sintered pellets obtained from milled BTO. P–E loops exhibited the expected relaxor-type slim hysteresis, with reduced Pᵣ (1.32 μC/cm2) and Ec (5.69 kV/cm). Milling also improved functional performance, the recoverable energy density (Wrec) increased from 0.22 to 0.31 J/cm3, while the energy storage efficiency (η) increased from 15 % to 85 %.本研究开发了一种简便且经济高效的方法，可在钛酸钡（BaTiO₃, BTO）陶瓷中诱导弛豫铁电行为。分别对未球磨与球磨制备的BTO粉体烧结坯体开展了X射线衍射（X-ray diffraction, XRD）、介电频谱表征以及极化-电场（P-E）测试。XRD结果证实，所有样品均保留了四方相P4mm晶体结构。介电频谱测试结果显示，未球磨粉体烧结坯体的介电响应呈现尖锐的居里峰（约120℃），而球磨后坯体的介电转变变为宽化的弥散相变（60℃~180℃），对应的弥散系数从0.52提升至1.30。压电力显微镜（Piezoresponse force microscopy）表征证实，球磨制备的BTO烧结坯体中形成了极性纳米区域。P-E迟滞回线呈现出典型的弛豫铁电型窄滞回特征，剩余极化强度Pᵣ（1.32 μC/cm²）与矫顽场E_c（5.69 kV/cm）均有所降低。此外，球磨工艺还优化了材料的功能性能：可回收储能密度（W_rec）从0.22 J/cm³提升至0.31 J/cm³，储能效率（η）从15%提升至85%。