Effect of Humidity Adsorption on Mixed Valence Dielectric Material LaFe 1− x Al x O 3
Effect of Humidity Adsorption on Mixed Valence Dielectric Material LaFe 1− x Al x O 3
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混合价态介电材料LaFe 1×Al x O 3 的湿度吸附效应
DOI：
10.1002/pssb.202000342
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Chunchang Wang
中科院分区：
文献类型：
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作者：
Rida Ahmed;Sajid ur Rehman;Renjun Si;Chunchang Wang
在混合价巨介电材料中，在过去的文献中，室温Maxwell-Wagner响应通常被分配给电极效应、晶界效应或内部势垒层电容器效应。另一个潜在的现象被忽略了，那就是氢氧根离子吸附到介电材料表面的缺陷中心上。介电材料的性能，特别是那些具有氧空位的介电材料，对大气湿度敏感，并且在潮湿环境中容易劣化。为了研究这种效应，我们采用溶胶-凝胶法制备了一系列LaFe 1 − xAlxO 3样品（x= 0，0.1，0.2，...，0.8和1），并观察了湿敏性对其介电性能的影响。具有更高Fe浓度的样品在两种金属电极（Pt和Ag）下显示出不同的湿敏特性，其测量值差异非常小。通过对样品进行热淬灭后的介电测量进一步证实了氢氧根离子的影响，该测量验证了水分子在介电材料表面上的吸附量。
In mixed‐valence colossal dielectric materials, the room temperature Maxwell–Wagner response is commonly assigned, in the past literature, to the electrode effect, grain boundary effect, or internal barrier layer capacitor effect. Another underlying phenomenon is brushed aside, and that is of adsorbance of the hydroxyl ions onto the defect centers on the surface of dielectric material. The properties of dielectric materials, especially those having oxygen vacancies, are sensitive to the atmospheric moisture and easily degrade in the humid environment. To study this effect, a series of LaFe1 −xAlxO3samples (x= 0, 0.1, 0.2, …, 0.8, and 1) are prepared by the sol–gel method, and the effect of humidity sensitivity on their dielectric properties is seen. The samples with greater Fe concentration show distinct humidity‐sensitive properties with both metal electrodes (Pt and Ag) with a very miniscule difference in their measurement values. The effect of hydroxyl ions is further confirmed by the dielectric measurements after the thermal quenching of the samples that verify the adsorbance of water molecules on the surface of dielectric material.