Quantitative measurement of amorphous grain boundary phase of aluminum nitride ceramics and correlation of microstructure and other physical properties with thermal conductivity

The amorphous grain boundary phase contents of aluminum nitride (AlN) was estimated by the linear combination fitting method of XAFS, which is new approach. C-axis lattice parameters of the AlN crystals and median diameters of the AlN grains were also measured and correlations with thermal conductivities of the ceramics were analyzed. As a result, the amorphous grain boundary phase contents showed a negative correlation. On the other hand, the c-axis parameters and the median diameters showed positive correlations. Furthermore, a multiple regression analysis showed that the three properties could approximately explain the thermal conductivity and that the amorphous grain boundary phase contents and the median diameters dominated.