Synthesis of a Series of Single-crystalline La 1-x Ca x MnO3 Nanowires by Hydrothermal Method

A series of single-crystalline La 1-x Ca x MnO 3 nanowires were successfully prepared by a hydrothermal method. X-ray diffraction (XRD) results demonstrate that theLa 1-x Ca x MnO 3 nanowires have orthorhombic perovskite structure without any impurity phases. Transmission electron microscope (TEM) images clearly show that the as-synthesized samples are made up of large quantities of single crystal nanowires with lengths ranging from several to several tens of micrometers and uniform diameter (about 90nm). The high-resolution transmission electron microscope(HRTEM)investigations of La 0.5 Ca 0.5 MnO 3 nanowires indicate that the nanowires have very clean surfaces without any defects and grow along <100> direction. The result of magnetic measurement indicates that the La 0.5 Ca 0.5 MnO3 nanowires have an enhanced Tc due to the shrinkage of unit cell volume and shape anisotropy.