  Pd-metal graphite (Pd-MG) has a layered structure, where each Pd sheet is
sandwiched between adjacent graphene sheets. DC magnetization and AC magnetic
susceptibility of Pd-MG have been measured using a SQUID magnetometer. Pd-MG
undergoes a superconducting transition at $T_{c}$ ($= 3.63 \pm 0.04$ K). The
superconductivity occurs in Pd sheets. The relaxation of $M_{ZFC}$ (aging),
which is common to spin glass systems, is also observed below $T_{c}$. The
relaxation rate $S(t)$ shows a peak at a characteristic time $t_{cr}$, which is
longer than a wait time $t_{w}$. The irreversibility between $\chi_{ZFC}$ and
$\chi_{FC}$ occurs well above $T_{c}$. The susceptibility $\chi_{FC}$ obeys a
Curie-Weiss behavior with a negative Curie-Weiss temperature ($-13.1 \leq
\Theta \leq -5.4$ K). The growth of antiferromagnetic order is limited by the
disordered nature of nanographites, forming spin glass-like behavior at low
temperatures in graphene sheets.
