  The magnetic properties of a quasi two-dimensional superconductor, Sn-metal
graphite (MG), are studied using DC and AC magnetic susceptibility. Sn-MG has a
unique layered structure where Sn metal layer is sandwiched between adjacent
graphene sheets. This compound undergoes a superconducting transition at
$T_{c}$ = 3.75 K at $H$ = 0. The $H$-$T$ diagram of Sn-MG is similar to that of
a quasi two-dimensional superconductors. The phase boundaries of vortex liquid,
vortex glass, and vortex lattice phase merge into a multicritical point located
at $T^{*}$ = 3.4 K and $H^{*}$ = 40 Oe. There are two irreversibility lines
denoted by $H_{gl}$ (de Almeida-Thouless type) and $H_{gl^{\prime}}$
(Gabay-Toulouse type), intersecting at $T_{0}^{\prime}$= 2.5 K and
$H_{0}^{\prime}$ = 160 Oe. The nature of slow dynamic and nonlinearity of the
vortex glass phase is studied.
