Synthesis and characterizations of layered cobalt oxides ACoO2 (A = Na, Li, Pt and Pd) for thermoelectric applications

Abstract

Layered cobalt oxides ACoO2 (A=Na, Li) were synthesized using soft hydrothermal method and structural properties were studied for Na0.6CoO2 and structural and magnetic properties were studied for LiCoO2.The obtained polycrystalline LiCoO2 shows good purity while the synthesis conditions are much lower compared to the available literature. Magnesium substituted polycrystalline samples of Na0.7CoO2 were obtained using binary oxide (CoMg)O as one of the precursors in solid state method and structural, magnetic and transport properties were studied. Mg substituted ACoO2 (A=Pt,Pd) single crystals were obtained using metathetical reactions with binary oxide (CoMg)O as one of the precursors and high level Mg substitutions were achieved. The structural, magnetic, transport and absorption properties were studied for Mg substituted PdCoO2 single crystals. Structural, magnetic and surface properties were studied for Mg substituted PtCoO2 crystals.