激光快速凝固法制备织构化二钛酸钡及其介电性能研究

Textured Barium Dititanate Obtained by Laser Rapid Solidification Method and Its Dielectric Properties

采用激光快速凝固法制备织构化（b轴择优取向）的二钛酸钡（BaTi2O5）铁电陶瓷,使用X射线衍射仪（XRD）和扫描电子显微镜（SEM）分析晶相构成及显微组织,利用精密阻抗分析仪测试介电性能。结果表明,激光快速凝固制备BaTi2O5为高纯单斜相,具有较高致密度（相对密度大于95.1%）和择优取向度（0.34-0.48）,其居里相变温度（Tc）约为443℃,居里温度点的最大介电常数（εmax）约为6000（100 kHz）,居里外斯温度（T0）为410℃,居里外斯常数（C）为2.08×105K。

Textured poly-crystalline barium dititanate（BaTi2O5,denote as BT2） ferroelectric ceramics with a preferred b-axis orientation are synthesized by a novelty method named laser rapid solidification.So-synthesized BT2 is with a higher density（relative density is larger than 95.1%）.The analysis of X-Ray diffraction（XRD） reveals that the samples are of high pure monoclinic phase and the grains grow along the b-axis direction with a reliability high Lotgering factor（0.34～0.48）.The observation of scanning electron microscopy（SEM） shows that the so-synthesized ceramics are composed of plate-like microstructure parallel to the laser incident direction.The Curie temperature（Tc） is about 443 ℃.The maximum dielectric constant（εmax,at Tc） is about 6000 at the frequency of 100 kHz.The Curie-Weiss temperature T0 and Curie-Weiss constant are 410 ℃ and 2.08×105 K,respectively.