不同晶粒度的La_(0.67)Sr_(0.33)MnO_3的吸波性能研究

Microwave Absorption Properties of La_(0.67)Sr_(0.33)MnO_3 with Different Particle-size

用溶胶-凝胶法合成了不同晶粒度的La0.67Sr0.33MnO3样本,研究了不同晶粒度材料的结构、磁性和微波吸收性质之间的关联.实验结果表明,可以通过改变烧结温度实现La0.67Sr0.33MnO3样品晶粒大小的控制;在一定的纳米尺度范围内,随着晶粒度的不断增大,吸波峰值逐渐向高频方向移动;晶粒度为58.5nm的样品在X波段有很好的吸波性能,反射损耗最大值达到RL-32dB,对应的频率点为10.1GHz,反射损耗的带宽达到1.6GHz.

La0.67Sr0.33MnO3 particles with different particle size are prepared by sol-gel method.The structure,magnetization and microwave absorption properties are investigated.The results show that the particle size can be controlled by sinter temperature.The peaks of the maximum reflection loss（RL） move to higher frequency regions with increasing particle size.The value of the maximum RL is-32 dB at 10.1 GHz with a particle size of 58.5nm.The bandwidth with a RL exceeding-8dB reaches 1.6GHz in the whole measured freqency range.