非化学计量化合物是针对组分成定比的化学计量化合物而言的。晶体化合物发生化学计量偏离是由于晶体内存在着原子或电子缺陷的关系。这对化合物的电、磁、光等性质发生影响是不言而喻的。不过更重要的还是因此在固体表面和相、粒界面上产生与体相不同的化学组成。近年来,正在研究和开发的一系列高技术材料,诸如压敏电阻(Varistor),正温度系数热敏电阻(PTCR Thermistor)、超导材料、光敏传感器件等,就是利用相界面和晶面上由这一效 Non-stoichiometric compounds are for stoichiometric compositional compounds. The stoichiometric deviation of crystalline compounds is due to the existence of atomic or electronic defects in the crystal. It is self-evident that this has an effect on the electrical, magnetic and optical properties of the compound. But more importantly, therefore, has a different chemical composition from the bulk phase on the solid surface and in the phase and grain boundaries. In recent years, a series of high-tech materials being researched and developed, such as Varistor, PTCR Thermistor, superconducting material, photosensitive sensor, etc., utilize phase interface and crystal plane By this effect