Magnetic Properties of Expanded Graphite Intercalation Compounds of CuCl_2-NiCl_2

The magnetization intensity and magnetic susceptibility of CuCl2-NiCl2-EGICs, synthesized with expanded graphite were measured with MODEL-155 vibration magnetometer under the magnetic field intensity (0-7.958×105A/m). The result showed that after CuCl2 and NiCl2 were intercalated into graphite layers, the magnetic properties of GICs were increased. The magnetic susceptibility of GICs was as about 10-100 times as that of pristine expanded graphite. GICs were paramagnetic. It was different from diamagnetic graphite. The slope of magnetization curve changed from negative number to positive. The magnetic property of GICs can change with the stage structure and the molar ratio of CuCl2 and NiCl2.Below 50% volume of NiCl2, GICs had a strong paramagnetic property; when it was 50%, GICs was ferromagnetic. When the ratio of NiCl2 was higher than 50% (60%、80% particularly), there was a maximum in their magnetization curve. It indicates that GIC is ferromagnetic. The higher the stage of GICs, the lower its ferromagnetic property is.