We show the successful intercalation of large area (1 cm$^2$) epitaxial few-layer graphene grown on 4H-SiC with FeCl$_3$. Upon intercalation the resistivity of this system drops from an average value of $approx 200 Omega/sq$ to $approx 16 Omega/sq$
at room temperature. The magneto-conductance shows a weak localization feature with a temperature dependence typical of graphene Dirac fermions demonstrating the decoupling into parallel hole gases of each carbon layer composing the FeCl$_3$ intercalated structure. The phase coherence length ($approx 1.2 mu$m at 280 mK) decreases rapidly only for temperatures higher than the 2-D magnetic ordering in the intercalant layer while it tends to saturate for temperatures lower than the antiferromagnetic ordering between the planes of FeCl$_3$ molecules providing the first evidence for magnetic ordering in the extreme two-dimensional limit of graphene.
We present the first systematic study of the stability of the structure and electrical properties of FeCl$_3$ intercalated few-layer graphene to high levels of humidity and high temperature. Complementary experimental techniques such as electrical tr
ansport, high resolution transmission electron microscopy and Raman spectroscopy conclusively demonstrate the unforeseen stability of this transparent conductor to a relative humidity up to $100 %$ at room temperature for 25 days, to a temperature up to $150,^circ$C in atmosphere and up to a temperature as high as $620,^circ$C in vacuum, that is more than twice higher than the temperature at which the intercalation is conducted. The stability of FeCl$_3$ intercalated few-layer graphene together with its unique values of low square resistance and high optical transparency, makes this material an attractive transparent conductor in future flexible electronic applications.
