Electronic Conductivity in the La ( Cr , Ni ) O 3 Perovskite System

Electrical conductivity measurements were carried out in the system by a four‐point dc method. The conductivities of and are 0.016 and 1000 Ω −1 cm −1 at room temperature and 0.759 and 250 Ω −1 cm −1 at 1000°C, both in flowing oxygen. The sample densities are 72 and 52% of the theoretical value, respectively. is a semiconductor; shows metallic conductivity behavior. Electrical conductivity measurements on solid solutions of these end members show that the transition from semiconducting to metallic conduction behavior occurs at the composition . The density of the solid solution samples ranges from 47 to 72% of the theoretical value. The electrical conductivity shows a linear dependence on the density that allowed us to normalize all conductivity data to 60% of theoretical density.