Investigation of multiferroic behaviour of TbMnO₃ nanoplates

Highlights: • Hydrothermal synthesis of TbMnO₃ nanoplate. • Morphology induced defects detected by Raman spectroscopy. • Magnetic and dielectric anomalies confirmed multiferroic behavior is retained in TbMnO₃ nanoplates. - Abstract: In the present study, hydrothermally prepared TbMnO₃ in plates-like morphology at nanoscale are investigated in multiferroic view point. X-ray diffraction study confirms the orthorhombic phase of as-synthesized TbMnO₃. Microstructural features studied by Scanning Electron Microscopy and Transmission Electron Microscopy show the plates-like morphology of as-synthesized TbMnO₃ at nanoscale. Local distortions investigated by FT-Raman exhibits redshift in T mode by about 20 cm⁻¹ as compared to that of the single crystal. The redshift in T mode is mainly due to defect by tilting of octahedra and respective changes in bond angle of Mn–O(1)–Mn. This is assigned to the size-morphology induced defects. The temperature dependent zero-field-cooled and field-cooled magnetization are measured at H = 50 Oe and in the temperature range 2–300 K. The anomalies in magnetization are obtained at 8 and 42 K. Bifurcation of the ZFC and FC curves are observed very close to magnetic transition temperature 42 K. The 42 K anomaly is related to the sine wave ordering of Mn³⁺ moment; and 8 K anomaly is associated with magnetic ordering of the Tb³⁺-sublattice propagation vector. The anomalies in the electric properties, ϵ′ (T), tan δ (T), which are noticed within the 28 K range, coincide with the temperature of incommensurate–commensurate (or lock-in) magnetic transition of TbMnO_3. This study confirms that multiferroic behavior is retained in TbMnO₃ nanoplates