Elemental substitution effects in multiferroic R Fe2O4 ( R: rare earths).

We report the effects of elemental substitutions in multiferroic R Fe2O4 ( R: Y, Ho-Lu, In). The substitution by nonmagnetic Ga3+ at the Fe site, which has not been reported so far, shows a drastic decrease in the ferrimagnetic transition temperature ( TN). This is plausibly owing to the suppression of magnetic interactions between Fe ions, based on our previous results of other substituted systems such as R FeCoO4. Dielectric constants near room temperature were comparable to those of R Fe2O4. The suppression of dielectric loss in this system is suitable to application. The R -site substitution was also attempted by the large R3+ ions such as Dy3+. The solubility limit was up to ∼10% of R ions. TN was raised by 5-10 K for Dy3+ substitution. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]