Transport and 13C nuclear magnetic resonance studies on potassium–ammonia intercalated graphite Original Research Article

We have synthesized and studied two new second stage graphite intercalation compounds of the K–NH3 family. The β′ variety KC8(NH3)0.55±0.05 possesses an interplanar distance di of 820 pm, while the T2 species, KC24(NH3)1.4±0.1 has di=645 pm. The latter compound with the smaller interplanar distance is shown to be a better in-plane conductor and to undergo a strong c-axis resistivity transition centered around 150 K, which NMR results suggest as being due to blocking of rotation of the NH3 molecules.