Enhanced magnetic property and magnetodielectric coupling effect in multiferroic Gd2BaCuO5 via Zn2+ doping.

The multiferroics with remarkable magnetoelectric (ME) coupling and technological application have drawn significant attention. Here, we report a chemical doping tunable effect on the magnetic, ferroelectric, and dielectric properties in type-II multiferroic Gd 2 BaCuO 5. The magnetic measurement results show that a long-range antiferromagnetic ordering forms at the Néel temperature (T N1) of ∼12.1 K, and a second magnetization anomaly occurs at a lock-in transition temperature (T N2) of ∼6.4 K. Sharp peaks in the pyroelectric and dielectric curves are observed at the magnetic transition temperatures, indicating intrinsic coupling between magnetic and ferroelectric orderings. The doping of Zn2+ results in a gradual enhancement of magnetization due to the increase of uncompensated spins, and large magnetodielectric (MD) coupling parameter up to ∼7.65 % is obtained in Gd 2 BaCu 0.7 Zn 0.3 O 5 because of strong spin-phonon coupling. The ferroelectric property is weakened in Zn2+ doped samples, suggesting the critical role of the 4 f -3 d magnetic interactions in determining the ME coupling effect. Moreover, an effective manipulation of electric field on magnetization is observed in Gd 2 BaCuO 5. This work helps understand the importance of 4 f -3 d magnetic interactions in inducing ferroelectricity and explore the ME and MD coupling effects with multiple magnetic orderings. [ABSTRACT FROM AUTHOR]