Abstract: Y_2.80Pr_0.20Fe₅O₁₂/Ba_0.6Sr_0.4TiO₃ thin film heterostructure was claimed by Jiao et al. in Journal of Materials Science & Technology 202 (2024) 174 as a tunable dielectric material with superior performance achieved under simultaneous application of the electric and magnetic fields at a particular frequency of 1.44 MHz. However, here we express concerns regarding the real presence of the phenomenon at 1.44 MHz in the studied structures based on the literature and dielectric spectroscopy principles. We also note that the presented dielectric results and their interpretations are contradictory.

Key words: Ba_1-xSr_xTiO₃, Dielectric spectroscopy, Tunability, Magnetoelectricity