Synthesis and characterization of intercalated few-layer graphenes

Abstract

Toward achieving room-temperature superconductivity, FeCl3-intercalated few-layer graphenes (FeCl3-FLGs) and Ca-intercalated few-layer graphenes (Ca-FLGs) were synthesized. FeCl3-FLGs were synthesized by the two-zone method and Ca-FLGs were synthesized using Ca–Li alloy. The Raman spectra of the FeCl3-FLGs showed a lower-intensity peak at 1607 cm−1 than that of the corresponding bare G. The peak at 1607 cm−1 suggested that the sample was stage 4–5 FeCl3-FLGs. The room-temperature electrical resistivity of FeCl3-FLGs was 2.65 × 10−5 Ω·m, which linearly decreased with decreasing temperature with a marked change occurring at approximately 200 K. From a XRD pattern of Ca-FLGs, we concluded that Ca is intercalated in FLGs. The room-temperature resistivity of Ca-FLGs was 3.45 × 10−5 Ω·m, which increased with decreasing temperature.