Effects of holmium substitution on multiferroic properties in Tb0.67Ho0.33MnO3

Abstract

In this work, the structural, electrical, and magnetic properties of orthorhombic TbMnO3 and Tb0.67Ho0.33MnO3 ceramics are presented. The lattice parameters and the Mn-O-Mn bond angle were found to decrease with Ho-substitution as evidenced by Rietveld refinement of the X-ray diffraction data and Raman spectroscopy measurements. A weak ferromagnetic moment was observed in both dc and ac magnetic measurements of the Ho-substituted sample possibly due to spin canting in the antiferromagnetic phase. Tb0.67Ho0.33MnO3 was confirmed to be multiferroic with appearance of spontaneous polarization below 25 K and an additional increase in polarization ∼15.5 K associated with the ordering of the Ho3+ moments.

Study of structure and magnetic ordering in multiferroics Tb1−Nd MnO3 by neutron powder diffraction

“…Only (0 0 1) ± s Mn peaks were observed in whole temperature range, indicating that the Tb magnetic ordering was completely suppressed due to the large magnetic field. The inset shows the temperature dependence of the intensity of the (0 0 1) ± s Mn peaks under 5 T. The transition temperature agrees with the T Mn N temperature of $42 K. It is well known that manganites exhibit magnetic properties that vary with the dopant radius and concentration [10][11][12]. To prove the importance of Tb-magnetic order in TbMnO 3 system, we prepared several samples of Tb 1Àx Nd x MnO 3 to check the influence of Tb disordering.…”

Large magnetoelectric coupling in nanoscaleBiFeO3from direct electrical measurements

“…Such a clear proof of the prevalence of magnetoelectric coupling in the nanoscale still does not exist in the literature on BiFeO 3 . It is important to mention here that the extent of change in ferroelectric polarization observed in nanoscale BiFeO 3 is comparable to the change (∼30-90%) observed in the ferroelectric polarization under a magnetic field (∼20-90 kOe) for wellknown type-II multiferroics such as TbMnO 3 [22,23], DyMnO 3 , [24] CuCrO 2 [25] etc. in bulk, thin film, or single crystal form with 3D or 2D magnetic structure.…”

Magnetic exchange interactions of rare-earth-substitutedDyCrO3bulk powders

“…Type II ME MFs (such as TbMnO 3 ), on the other hand have intrinsically high ME coupling as the ferroelectricity is believed to be induced by some magnetic order in the material. [4,5] However, this magnetically driven ferroelectricity typically commences at cryogenic temperatures (for example ~ 27 K for TbMnO 3 ). [4,5] ME MFs with strong ME coupling at ambient temperature have great potential for their applications in novel low-power RAM architectures, new programmable, low-power logic gate designs, etc.…”

“…[4,5] However, this magnetically driven ferroelectricity typically commences at cryogenic temperatures (for example ~ 27 K for TbMnO 3 ). [4,5] ME MFs with strong ME coupling at ambient temperature have great potential for their applications in novel low-power RAM architectures, new programmable, low-power logic gate designs, etc. [6,7] Thus in order to design such ME MFs suitable for these applications, either the ordering temperatures of Type II ME MFs needs to be increased or the ME coupling in Type I ME MFs need to be enhanced.…”