Metal-insulator transition inCa1−xLixPd3O4

Abstract

Metal-insulator transition in ${\mathrm{Ca}}_{1\ensuremath{-}x}{\mathrm{Li}}_{x}{\mathrm{Pd}}_{3}{\mathrm{O}}_{4}$ has been studied through charge transport measurements. The resistivity, the Seebeck coefficient, and the Hall coefficient are consistently explained in terms of a simple one-band picture, where a hole with a moderately enhanced mass is itinerant three dimensionally. Contrary to the theoretical prediction [Phys. Rev. B 62, 13 426 (2000)], ${\mathrm{CaPd}}_{3}{\mathrm{O}}_{4}$ is unlikely to be an excitonic insulator, and holds a finite carrier concentration down to 4.2 K. Thus the metal-insulator transition in this system is basically driven by localization effects.