高能球磨制备钛酸锶铋陶瓷及其介电弛豫研究

采用高能球磨和固相烧结法制备了一系列Sr1-1.5xBixTiO3(SBT)陶瓷.采用XRD和SEM分析了样品的相结构和显微结构.结果表明,高能球磨过后的粉末为具有钙钛矿结构的SBT固溶体,且SBT陶瓷的固溶度有所提高.其介电性能结果表明,SBT的介电常数温度特性具有明显的弛豫现象,并且随Bi含量的增加,相转变温度向高温移动,相变弥散及弛豫程度增强,并对SBT陶瓷的弛豫机制进行了探讨.

Dielectric relaxation investigation of Sr1-1.5xBixTiO3 ceramics prepared by high-energy ball milling

A series of Sr1-1.5xBixTiO3 ceramics were prepared by the conventional solid reaction using high-energy ball milling method. The crystalline structure and morphology were studied by XRD and SEM, respectively. Experimental results show that the high-energy ball milled powders demonstrated a typical perovskite crystalline structure, and the solubility of bismuth oxide in strontium titanate was enhanced. The dielectric constant as a function of temperature was investigated. The dielectric properties of Bi doped Sr1-1.5Bix TiO3 ceramics show that a clear relaxor behavior could be observed in the temperature dependence of the dielectric constant. With the increase in Bi doping, the phase transition temperature shifts to higher temperature, and the degree of the diffuseness and the relaxation increases. A random electric field is suggested to be responsible for the relaxor behavior observation.