Phase transition inAlCl3-graphite as seen by the thermal hysteresis in the conduction-carrier spin resonance

A phase transition at 168 K has been recognized from the thermal hysteresis of the conduction-carrier spin-resonance parameters in the stage-7 acceptor ${\mathrm{AlCl}}_3$-graphite intercalated compound (GIC). Below the transition temperature, the final low-temperature in-plane residual resistivity of the sample was found to be dependent on its previous thermal history. Paradoxically, quenching effects, contrary to previous reports on low-stage acceptor GIC’s, leave the system in an ‘‘orderedlike’’ state of higher in-plane conductivity.