Spin reorientation and spin-flop transition in multiferroic manganites Y1–xTbxMnO3 (x = 0, 0.1, 0.2) single crystals

Abstract

We investigated the structure and magnetic properties of the multiferroic hexagonal manganite Y1−xTbxMnO3 (x = 0, 0.1, 0.2) single crystals. At 23 K, a Mn spin reorientation transition, which is not reported in the parent compound YMnO3, is observed in Y0.8Tb0.2MnO3. At a lower temperature, another new transition is observed in the doping system, which is attributed to the formation of long range antiferromagntic order of the doped Tb3+ moments. Based on the experimental results, we suggest that the effect of Tb doping is to bring about the increase of the Mn-O-Mn bond angle and the relief of the magnetic frustration. With increasing the doping level, for x = 0.2, when a magnetic field is applied parallel to the c axis, the field induced spin-flop transition is appeared, which indicates the reorientation of the Mn3+ moments along with the field-induced ferromagnetic ordering of the Tb3+ moments. These results suggest that the possibility of the Tb doping can change the magnetic structure and ferroelectricity properties of YMnO3.

Spin-flop and magnetodielectric reversal in Yb substituted GdMnO3

“…In addition, M-H plots show a regular 'S' shape for x = 0 and 0.05 and an irregular one with a change in curvature at sufficiently high H field for x = 0.1 and 0.15 compositions. This feature is more prominent in single crystalline materials where H field can be applied along the easy axis of the twosublattice AFM system [31,32]. The irregular 'S' shape in AFM materials can be an indication for a spin-flop transition.…”

Revealing magnetic ordering and spin-phonon coupling in Y1−x Tb x MnO3 (0.1 ⩽ x ⩽ 0.3) compounds

“…Using this technique we get a direct measure of the magnitude and orientation of the magnetic spins, which are essential for investigating such terbium substituted yttrium manganites. A microscopic understanding of the magnetic ordering of Mn 3+ and Tb 3+ ionic moments and their intertwined correlations with the crystal structure (as conjectured by Li et al [3]) has been obtained by employing a powerful microscopic neutron diffraction technique down to 2.8 K. The understanding has been further strengthened by us by employing temperature dependent Raman scattering study where a spin-phonon coupling has been established. The present work, therefore, gives an in depth understanding of the coupled structural and magnetic correlations in the Y 1−x Tb x MnO 3 (0.1 ⩽ x ⩽ 0.3) compounds.…”

“…In this sample the ratio of |Θ C-W |to T N is ~0.7, (inset of figure 1(b)). Li et al [3]. also carried out Curie-Weiss analysis on the temperature dependent dc magnetization data for the samples Y 1−x Tb x MnO 3 (0 ⩽ x ⩽ 0.2).…”

“…That is the reason we undertook this study to have a microscopic understanding of the reported role of Tb substitution on the bulk properties of the Y 1−x Tb x MnO 3 (0.1 ⩽ x ⩽ 0.3) compounds. In ref [3], the authors had found a Mn spin reorientation transition at 23 K in Y 0.8 Tb 0.2 MnO 3 (which is not reported in the parent compound YMnO 3 ). They also found that at a lower temperature there was another new transition for the 20% Tb substituted compound, and attributed it to the formation of a long range antiferromagnetic order of the substituted Tb 3+ ionic moments.…”

“…Li et al [3] reported, by employing magnetometry that with increased substitution of Tb a change in the structural, magnetic and ferroelectric properties of the Y 1−x Tb x MnO 3 (0.1 ⩽ x ⩽ 0.3) compounds can be achieved, from that of the end member compounds. That is the reason we undertook this study to have a microscopic understanding of the reported role of Tb substitution on the bulk properties of the Y 1−x Tb x MnO 3 (0.1 ⩽ x ⩽ 0.3) compounds.…”