钇和镧掺杂氧化铝陶瓷的热导及其介电弛豫特性研究

Influences of Y- and La-dopant on the thermal conductive properties and dielectric relaxation of Al_2O_3-based ceramics

采用氧化物固相反应法,制备出纯氧化铝陶瓷及其分别掺杂稀土元素钇和镧的陶瓷样品.测量了样品的结构、介电特性和热导性能;研究了烧结温度对掺杂不同稀土元素的陶瓷样品的性能的影响.X射线衍射结果表明1500℃烧结后陶瓷样品形成了单一的固溶体.而氧化铝的热导率达到8.60W/(m·K),样品的介电性能稳定.我们发现掺杂Y^(3+)和La^(3+)的氧化铝陶瓷存在介电弛豫现象,并对该现象进行了机理分析.

Al2O3 ceramics doping with Y3＋ and Las＋ are synthesized by conventional solid state reaction method. The structures, thermal conductivities properties and the effects of sintering temperature on the electrical properties of the samples are measured. X-ray diffraction results indicate that all the ceramics are formed to be of pure solid solution when the samples are sintered at 1500 ℃. Thermal conductivities of Al2O3 ceramics reach up to 8.60 W/（m.K）. All the ceramics show temperature-stable dielectric characteristics. Typical dielectric relaxation behaviors are observed in Y- and La-doped Al2O3 ceramics, and the relaxation mechanism is also analyzed.