  Titanium disulfide TiS$_2$, which is a member of layered transition-metal
dichalcogenides with the 1T-CdI$_2$-type crystal structure, is known to exhibit
a wide variety of magnetism through intercalating various kinds of
transition-metal atoms of different concentrations. Among them, Fe-intercalated
titanium disulfide Fe$_x$TiS$_2$ is known to be ferromagnetic with strong
perpendicular magnetic anisotropy (PMA) and large coercive fields
($H_\text{c}$). In order to study the microscopic origin of the magnetism of
this compound, we have performed x-ray absorption spectroscopy (XAS) and x-ray
magnetic circular dichroism (XMCD) measurements on single crystals of
heavily-intercalated Fe$_x$TiS$_2$ ($x\sim0.5$). The grown single crystals
showed a strong PMA with a large $H_\text{c}$ of $\mu_0H_\text{c} \simeq 1.0\
\text{T}$. XAS and XMCD spectra showed that Fe is fully in the valence states
of 2+ and that Ti is in an itinerant electronic state, indicating electron
transfer from the intercalated Fe atoms to the host TiS$_2$ bands. The
Fe$^{2+}$ ions were shown to have a large orbital magnetic moment of $\simeq
0.59\ \mu_\text{B}\text{/Fe}$, to which, combined with the spin-orbit
interaction and the trigonal crystal field, we attribute the strong magnetic
anisotropy of Fe$_x$TiS$_2$.
