Hydrogen-sorption capacity and transport properties of potassium-graphite intercalation compounds

抄録

Potassium-graphite intercalation compounds with 7 different compositions ranging from KC₃₀₀ to KC₂₄ were prepared from exfoliated graphite sheet (Grafoil). Resistivity, magnetoresistance and hydrogen-sorption capacity of these compounds were determined. KC₃₀₀ and KC₂₅₀ showed semi-conductive temperature dependence of the resistivity as well as host Grafoil, while KC₁₆₈ and more rich compounds showed metallic behavior. Dependence of the resistivity and magnetoresistance on the potassium concentration was divided into two regions with a critical concentration at about KC_60-70. Both of these properties decreased considerably with increasing potassium concentration below this critical concentration, and then became almost constant above it. A remarkable correlation between transport properties and hydrogen-sorption capacity was suggested.