Comment on "Unconventional enhancement of ferromagnetic interactions in Cd-doped GdFe2Zn20 single crystals studied by ESR and 57Fe Mossbauer spectroscopies"

In the recent publication, Phys. Rev. B 102, 144420 (2020), Cabrera-Baez et al. present a study of the effects of Cd-substitution for Zn in the ferromagnetic compound GdFe2Zn20. As part of this paper, they claim that for GdFe2Zn18.6Cd1.4 the effective moment of Gd is reduced by 25% and the saturated moment of Gd is reduced by over 40%. We regrew representative members of the GdFe2Zn(20-x)Cdx series and did not find any such reductions. In addition, we measured several crystals from the growth batch that was used by Cabrera-Baez et al. and did not see such reductions. Although there is a modest increase in TC with Cd substitution, there is no significant change in the Gd effective moment or the saturated moment associated with the low temperature ferromagnetic state.