Growth and Physical Property Study of Single Nano wire (Diameter∼ 45 nm) of Half Doped Manganite

We report here the growth and characterization of functional oxide nano wire of hole doped manganite of La_0.5Sr_0.5MnO₃ (LSMO). We also report four-probe electrical resistance measurement of a single nano wire of LSMO (diameter ∼45 nm) using focused ion beam (FIB) fabricated electrodes. The wires are fabricated by hydrothermal method using autoclave at a temperature of 270 °C. The elemental analysis and physical property like electrical resistivity are studied at an individual nano wire level. The quantitative determination of Mn valency and elemental mapping of constituent elements are done by using Electron Energy Loss Spectroscopy (EELS) in the Transmission Electron Microscopy (TEM) mode. We address the important issue of whether as a result of size reduction the nano wires can retain the desired composition, structure, and physical properties. The nano wires used are found to have a ferromagnetic transition (T_c ) at around 325 K which is very close to the bulk value of around 330 K found in single crystal of the same composition. It is confirmed that the functional behavior is likely to be retained even after size reduction of the nano wires to a diameter of 45 nm. The electrical resistivity shows insulating behavior within the measured temperature range which is similar to the bulk system.