Journal of Materials Science, Vol.48, No.7, 2823-2828, 2013
Reversible control of the electronic density of states at the Fermi level of Ca3Co4O9+delta misfit-layered oxide single crystals through O+/H+ plasma exposure
Misfit-layered Ca3Co4O9 crystals were grown and characterized via XRD, SEM, and photo-emission spectroscopy (PES). The evolution of the intensity at the Fermi level (E (F)) with varying oxygen content was studied by PES. Oxygen species were successfully introduced and removed through O+ and H+ microwave-plasma (2.45 GHz, 2-5 mbar) treatments, respectively. A 5 min O+ plasma exposure was observed to result into a drastic enhancement in the E (F) intensity, demonstrating the influence of oxygen content to the charge carrier population in layered cobalt-oxide materials.