采用介电弛豫和内耗技术,并结合XRD技术研究了新型氧离子导体La_2Mo_(2-x)W_xO_9(x=0、0.25、0.5、0.75、1.0、1.2、1.4)的氧离子扩散行为和相变机制.结果表明,在La_2Mo(2-x)W_xO_9的介电损耗-温度谱和内耗-温度谱上均出现了2个损耗峰,其中低温峰对应氧离子的扩散弛豫过程,高温峰对应氧离子/空位分布的静态无序态到动态无序态的转变.
The effects of tungsten doping on the oxygen-ion diffusion and the phase transition in La_2Mo_(2-x)W_xO_9 samples(x=0, 0. 25, 0. 5, 0. 75, 1. 0, 1. 2, 1. 4) are studied using dielectric relaxation, internal friction and the XRD measurements. The results show that two peaks are detected in the dielectric loss-temperature spectra and the internal friction-temperature spectra of La_2Mo_(2-x)W_xO_9 samples. The low-temperature relaxation peak is associated with oxygen ion diffusion, and the high-temperature peak is associated with a phase transition from static disordered state to dynamic disordered state of oxygen ion/vacancy distributioa
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