Enhanced high temperature microwave absorption of La0.9Sr0.1MnO3/MgAl2O4 composite ceramics based on controllable electrical conductivity
Enhanced high temperature microwave absorption of La0.9Sr0.1MnO3/MgAl2O4 composite ceramics based on controllable electrical conductivity
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DOI：
10.1016/j.jeurceramsoc.2020.01.010
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发表时间：
2020-05
影响因子：
5.7
通讯作者：
Hongyao Jia;Wan-cheng Zhou;Hanyi Nan;Chunhai Wang;Yuchang Qing;F. Luo;Dongmei Zhu
中科院分区：
文献类型：
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作者：
Hongyao Jia;Wan-cheng Zhou;Hanyi Nan;Chunhai Wang;Yuchang Qing;F. Luo;Dongmei Zhu
通过对xLa0.9Sr0.1MnO3/（1 − x）MgAl 2 O 4复合陶瓷的晶体结构、电导率和介电常数的研究，研究了其高温微波吸收效率。掺杂后的样品保持了La0.9Sr0.1MnO3和MgAl 2 O 4的晶体结构，但Mn 3+和Al 3+离子发生了交换。复合陶瓷的电导率和介电常数随La0.9Sr0.1MnO3含量和测试温度的增加而增加。当x = 0.36时，La0.9Sr0.1MnO3的电导率显著提高了复合陶瓷的高温微波极化。根据透射/反射模型，x = 0.24的复合陶瓷在最佳厚度1.8 mm附近显示出优异的HTMAE。虽然x = 0.36的复合材料的最佳厚度减小到1.1 mm，但由于阻抗失配，HTMAE严重降低。xLa0.9Sr0.1MnO3/（1 − x）MgAl 2 O 4是一种很有前途的高温薄而高效的微波吸收材料，通过调节La0.9Sr0.1MnO3的电导率可以进一步提高微波介电常数。
The high temperature microwave absorbing efficiency (HTMAE) of xLa0.9Sr0.1MnO3/(1 − x)MgAl2O4composite ceramics was investigated by studying the crystal structure, electrical conductivity, and permittivity. The crystal structure of La0.9Sr0.1MnO3and MgAl2O4were maintained, but the Mn3+and Al3+ions were exchanged with each other through doping. The conductivity and permittivity of the composite ceramics increased with the increase of La0.9Sr0.1MnO3content and test temperature. When x = 0.36, the electrical conductivity in La0.9Sr0.1MnO3significantly enhanced the microwave polarization of the composite ceramics at high temperature. According to transmission/reflection modelling, the composite ceramics with x = 0.24 showed excellent HTMAE near the optimal thickness of 1.8 mm. Although the optimal thickness of the composite with x = 0.36 was reduced to 1.1 mm, the HTMAE was seriously lessened due to an impedance mismatch. xLa0.9Sr0.1MnO3/(1 − x)MgAl2O4are promising as thin and efficient microwave absorbing materials at high temperatures and the microwave permittivity can be further enhanced by adjusting the conductivity of La0.9Sr0.1MnO3.