  Recently, Sharma et al. [Adv. Sci. 9, 2203473 (2022)] claimed that thin films
(around 20 nm) of UO2 deposited on perovskite substrates exhibit strongly
enhanced paramagnetism (called induced ferromagnetism by the authors). Moments
of up to 3 Bohr magneton/U atom were claimed in magnetic fields of 6 T. We have
reproduced such films and, after characterisation, have examined them with
X-ray circular magnetic dichroism (XMCD) at the uranium M edges, a technique
that is element specific. We do not confirm the published results. We find a
small increase, as compared to the bulk, in the magnetic susceptibility of UO2
in such films, but the magnetisation versus field curves, measured by XMCD, are
linear with field and there is no indication of any ferromagnetism. The absence
of any anomaly around 30 K (the antiferromagnetic ordering temperature of bulk
UO2) in the XMCD signal suggests the films do not order magnetically.
