From the perspective of technical principles, electronic ceramic materials primarily leverage the crystal structure, grain boundary characteristics, and the electronic effects of dopant elements inherent to ceramic materials to achieve specific electrical properties. For instance, by controlling the purity and grain size of alumina ceramics, ceramic substrates can be fabricated that exhibit low high-frequency loss and stable dielectric constants, making them suitable for the packaging of high-speed integrated circuits. Conversely, by doping with rare earth elements-such as lanthanum and strontium-the piezoelectric properties of barium titanate ceramics can be significantly enhanced, establishing them as core materials for ultrasonic sensors and transducers.
Electrical Properties: Origin in Microscopic Defects and Polarization Behavior
The electrical characteristics of electronic ceramics are intimately linked to the point defects and line defects present within their crystal structures. Under the influence of an electric field, these defects can form electric dipoles and undergo rearrangement, thereby giving rise to properties such as high dielectric constants and low dielectric loss.
Electronic Conduction Mechanism: Carrier Excitation
Traditional ceramics typically function as insulators; however, through the process of doping-such as the addition of Bi₂O₃ to ZnO-valence electrons can acquire sufficient energy to transition into free electrons or holes, thereby enabling electrical conduction. The resulting conductive properties are significantly influenced by the grain boundary structure and the specific fabrication processes employed.