Effect of Samarium Oxide Addition on Electrical Resistivity of Hot-Pressed Aluminum Nitride

Abstract

The electrical resistivity of hot-pressed AlN with 0.1 to 4.8 wt% Sm₂O₃ addition was investigated. A minimum of 0.5wt% Sm₂O₃ addition decreases the resistivity of AlN ceramics at room temperature from more than 10¹⁴ ohm-cm to the range of 10¹⁰ to 10¹² ohm-cm. The activation energy of the resistivity is around 0.3 eV, which is about half that of AlN with Y₂O₃ addition with a resistivity in the same range. SPM and EPMA analyses showed that the conductive path was a grain boundary phase composed of Sm, Al, and O, which formed a three-dimensional network structure. This AlN ceramics with Sm₂O₃ addition has the feature that its electrical conduction behavior is characterized by a small amount of the grain boundary phase.