Critical behavior and the absence of glass state in ferromagnetic La0.7Ca0.3CoO3 nanowires

• Main Authors: Wang, Yang, Fan, Hong Jin
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2013
• Online Access: https://hdl.handle.net/10356/96621; http://hdl.handle.net/10220/10366
• Institution: Nanyang Technological University

We report a systematic study of the magnetic and thermodynamic properties of uniform La0.7Ca0.3CoO3 nanowires prepared by a hydrothermal method, and compare them with the bulk counterpart. The nanowires, ∼59 nm in diameter, are single crystalline as revealed by electron microscopy. With decreasing temperature, the bulk La0.7Ca0.3CoO3 shows a ferromagnetism followed by a reentrant glass state, whereas the nanowires show only a purely ferromagnetic ground state. The thermopower and specific heat results indicate that there exist enhanced spin and/or orbital fluctuations in the nanowires that could be responsible for the absence of the glass state. Critical behavior analysis shows that the nanowires fall into a three-dimensional Heisenberg ferromagnet class.