Synthesis and properties of single crystal TbMn₂O₅ nanostructures

Single crystal nanowire clusters of multiferroic material TbMn₂O₅ were obtained through a two-step synthesis. These TbMn₂O₅ nanowires have high crystallinity and a high aspect ratio. They can be as long as tens of micrometers with a minimum diameter of about 20 nm. Analysis based on HRTEM demonstrates their growth direction is along (001). Their growth mechanism was discussed. In the case of magnetism, TbMn₂O₅ nanowires turn out to be paramagnetic at high temperature and weakly ferromagnetic at low temperature. ZFC and FC curves separated below about 45 K and a transition peak at 4 K of ZFC is observed. A magnetic hysteresis loop of TbMn₂O₅ measured at 5 K shows a coercivity of 35 Oe. Measurements of the dielectric constant ε and dielectric loss tanδ reflect a sustainable upward rising (especially above 200 K) and this tendency increased with the drop of frequencies. Under lower frequencies the peak positions of the dielectric loss shifted towards higher temperature.