Electronic transport phenomena in single-crystal NiO and CoO

Abstract

Hall effect, conductivity and Seebeck measurements have been made on a series of NiO and CoO crystals containing up to approximately 0.6 at.% Li in the range 150-1100 °K. The results are interpreted in terms of 3d conduction in a narrow band and indicate that impurity conduction is dominant in many samples up to 200-300 °K, even when no Li is added. The isotropy of conduction in single domains of NiO suggests that 3d conduction depends on indirect overlap through the oxygen ions, rather than direct 3d overlap.