Investigations were made of the structural parameters and temperature dependences of dielectric properties of aluminium nitride ceramics synthesized by various methods using powders with sintering additives. The separation of resistivities and capacitances of structural fragments and their interfaces using Coule diagrams allows one to assume a preferential influence of boundaries on the charge carrier transport and dielectric properties. Investigations of the structural parameters made it possible to propose a block model of its building: a fragment of size dr which is free of macrodefects; the d-size crystallite consisting of dr regions divided by dislocations and/or stacking faults, and the crystallite aggregate of size D. All impurity phases are involved in the aggregate interfaces. The results shows that the conductivity is generally determined by the sizes dr and d rather than D. Impurity phases have a weak influence on electric conductivity in the region of the intrinsic charge carrier transport, especially at T > 600 K.
|Number of pages||10|
|Journal||Physica Status Solidi (A) Applied Research|
|Publication status||Published - Nov 1989|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics