Magnetism in Pd-graphite and paramagnetic Pd-GICs

In Pd-G and Pd-GIC, Pd nanoparticles are sandwiched between adjacent graphite layers. Samples were prepared by reduction of PdCl₂ GIC precursor by hydrogen gas for 2 h at 350 °C (Pd-G(1)), hydrogen gas for two days at 400 °C (Pd-G(2)), and by Li-diphenylide in THF at room temperature (Pd-GIC). There is a charge transfer between Pd and graphite layers for Pd-GIC, but no charge transfer for Pd-G. Magnetic properties of Pd-G and Pd-GIC have been studied using SQUID magnetization measurements. Pd-GIC shows a paramagnetic behavior with P_eff = (0.54 ± 0.05)μ_B. Pd-G(1) behaves like a antiferromagnetic itinerant spin system (T_N = 3.8 K). Pd-G(2) behaves like a quasi-2D XY-like ferromagnet with very weak antiferromagnetic interplanar interaction (T_cu = 14.2 K and T_cl = 11 K).