Extraordinarily large intrinsic magnetodielectric coupling of Tb member within the Haldane spin-chain family, R2BaNiO5

Abstract

The Haldane spin-chain compound, Tb2BaNiO5, has been known to order antiferromagnetically below (T_N= ) 63 K. The present magnetic studies on the polycrystals bring out that there is another magnetic transition at a lower temperature (T_2= ) 25 K, with a pronounced magnetic-field induced metamagnetic and metaelectric behavior. Multiferroic features are found below T_2 only, and not at T_N. The most intriguing observation is that the observed change of dielectric constant is intrinsic and largest (e.g., about 18% at 15 K) within this Haldane spin-chain family, R2BaNiO5. Taking into account that this trend (the largest change for Tb case within this family) correlates with a similar trend in T_N (with the values of T_N being about 55, 58, 53 and 32 K for Gd, Dy, Ho and Er cases), we believe that an explanation usually offered for this T_N behavior in rare-earth systems is applicable for this behavior as well . That is, single-ion anisotropy following crystal-field splitting is responsible for this extraordinary magnetodielectric effect in this Tb case. To our knowledge, such an observation was not made in the past literature of multiferroics.

4 figures; Physical Review B (in press)

References in corpus (5)

• Multiferroic materials and magnetoelectric physics: symmetry, entanglement, excitation, and topology
• Observation of a multiferroic critical end point
• Magnetoelectric Phase Diagrams of Multiferroic GdMn2O5
• Magnetic and dielectric behavior of the spin-chain compound Er2BaNiO5 well below its Néel temperature
• Multiferroicity and magneto-electric effect in Gd${}_2$BaNiO${}_5$

Cited by in corpus (7)

• Magnetic and transport anomalies in R2RhSi3 (R= Gd, Tb, and Dy), resembling those of an exotic magnetic skyrmion Gd2PdSi3
• Existence of a critical canting angle of magnetic moments to induce multiferroicity in the Haldane spin-chain system, Tb2BaNiO5
• Enhancement of magnetodielectric coupling in 6H-perovskites Ba3RRu2O9 for heavier rare earth cations (R=Ho,Tb)
• Multiferroicity in a spin-chain compound, Tb2BaCoO5, with exceptionally large magnetodielectric coupling in polycrystalline form
• Large magnetodielectric coupling in the vicinity of metamagnetic transition in $6H-$perovskite Ba${}_3$GdRu${}_2$O${}_9$
• Destruction of multiferroicity in Tb2BaNiO5 by Sr doping and its implication to magnetoelectric coupling
• Canting angle behavior of magnetic moments in Y- substituted Tb2BaNiO5 and its relevance for magnetoelectric coupling