  Fe3-xGeTe2 is an itinerant ferromagnet composed of two-dimensional layers
weakly connected by van der Waals bonding that shows a variety of intriguing
phenomena. Inelastic neutron scattering measurements on bulk single crystals of
Fe2.75GeTe2 were performed to quantify the magnetic exchange interaction
energies and anisotropy. The observed inelastic excitations are indicative of
dominant in-plane correlations with negligible magnetic interactions between
the layers. A spin-gap of 3.9 meV is observed allowing a measure of the
magnetic anisotropy. As the excitations disperse to their maximum energy (~65
meV) they become highly damped, reflective of both the magnetic site occupancy
reduction of 25{\%} on one Fe sublattice and the itinerant interactions. A
minimal model is employed to describe the excitation spectra and extract
nearest neighbor magnetic exchange interaction values. The temperature
evolution of the excitations are probed and correlations shown to persist above
Tc, indicative of low dimensional magnetism.
