  Magnetic van der Waals materials are often proposed for use in future
spintronic devices, aiming to leverage the combination of long-range magnetic
order and near-atomic thinness to produce energy-efficient components. One
class of material that has been discussed in this context are the iron halides
FeCl$_2$ and FeBr$_2$, which are A-type antiferromagnets with strong uniaxial
magnetocrystalline anisotropy. However, despite characterization of the bulk
materials, the possibility for sustaining the magnetic behaviors that would
underpin such applications in thin flakes has not been investigated. In this
work, we use nitrogen-vacancy (NV) center microscopy to quantitatively image
magnetism in individual exfoliated flakes of these iron halides, revealing the
absence of magnetic remanence, a weak induced magnetization under bias field
and variable behavior versus temperature. We show that our results are
consistent with the antiferromagnetic behavior of the bulk material with a soft
ferromagnetic uncompensated layer, indicating that extended ($>1~\mu$m)
ferromagnetic domains are not sustained even at low temperatures (down to 4 K).
Finally, we find that the magnetic order is strongly affected by the sample
preparation, with a surprising diamagnetic order observed in a thin, hydrated
sample.
