  Using X-ray magnetic circular dichroism (XMCD) measurements, we explore the
possible existence of induced magnetic moments in thin Pt films deposited onto
the ferrimagnetic insulator yttrium iron garnet (Y3Fe5O12). Such a magnetic
proximity effect is well established for Pt/ferromagnetic metal
heterostructures. Indeed, we observe a clear XMCD signal at the Pt L3 edge in
Pt/Fe bilayers, while no such signal can be discerned in XMCD traces of
Pt/Y3Fe5O12 bilayers. Integrating the XMCD signals allows to estimate an upper
limit for the induced Pt magnetic polarization in Pt/Y3Fe5O12 bilayers.
