室温条件下，掺镧钛酸钡多晶陶瓷传感元件电阻随着湿度的增加而下降三个数量级（相对湿度变化范围：３３—９４％）。采用溶胶－凝胶工艺，以醋酸镧、醋酸钡及钛酸丁酯为起始物，湿凝胶经５０℃干燥制得干凝胶，部分干凝胶在８００℃／２ｈ的焙烧条件下制备纳米多晶粉体，另一部分干凝胶经研细过筛之后，埋渗电极和等静压成型为素坯，在１３５０—１４００℃／１ｈ的条件下烧结而成为陶瓷，再经封装和老化即组装成为陶瓷元件．元件的湿敏特性则采用ＲＬＣ－直流电桥阻抗仪加以测试，其阻－湿线性相关系数ｒ＝０．９９３１，灵敏度Ｓ＝Ｒ＿（３３％ＲＨ）／Ｒ＿（９４％ＲＨ）≥１０～３。文中利用多种手段对干凝胶原粉、掺镧多晶粉体以及陶瓷进行了结构表征．ＦＴ—ＩＲ Ｒ Ｒ干凝胶含羟基，说明凝胶前驱体发生了水解反应。ＸＲＤ证明掺镧多晶粉体及陶瓷具有四方晶相结构，原始晶粒尺寸为纳米级且随焙烧温度增高而变大（１３．６－３７．３ ｎｍ）。ＳＥＭ对粉体及陶瓷的外观形貌进行了观察：表明粉体原始晶粒发生了团聚作用，形成了不同形貌的团聚颗粒，团粒疏松而多孔．团粒的尺寸属于微米级（１—１０μｍ）；多晶陶瓷的晶粒外观呈四方晶相，尺寸分布比较均匀，平均约０．８μｍ，具有清晰的晶界和空 At room temperature, the resistivity of lanthanum-doped barium titanate polycrystalline ceramic sensor decreased by three orders of magnitude with the increase of humidity (relative humidity range: 33-94%). Using sol-gel process, lanthanum acetate, barium acetate and butyl titanate as starting material, the wet gel was dried at 50 ℃ to obtain a xerogel, a portion of the xerogel was calcined at 800 ℃ / 2h After the nano-polycrystalline powder and the other part of the xerogel are grinded and sieved, the electrode is immersed and isostatically pressed into a green body and sintered at 1350-1400 ° C / 1h to become a ceramic, then encapsulated and aged That is, assembled into a ceramic component. The humidity characteristics of the components were tested by RLC-DC bridge impedance meter. The linearity coefficient of resistance-wetness was 0.9931, the sensitivity was S = R 33% RH / R 94% RH. In this paper, a variety of means of dry gel powder, lanthanum-doped polycrystalline powders and ceramics were characterized. The FT-IR R R gel contains hydroxyl groups, indicating that the gel precursor has undergone a hydrolysis reaction. XRD shows that the lanthanum-doped polycrystalline powders and ceramics have a tetragonal crystal structure, the original grain size is nanometer and increases with the calcination temperature (13.6-37.3 nm). The appearance of the powders and ceramics was observed by SEM. The results showed that the original grains of the powders were agglomerated and formed agglomerated particles with different morphologies. The aggregates were loose and porous. The size of the pellets is in the micron range (1-10μm). The grain appearance of the polycrystalline ceramics is tetragonal with a uniform size distribution of about 0.8μm on average, with clear grain boundaries and gaps