We report the synthesis of MnO2-delta microspheres using hydrothermal and conventional chemical reaction methods. The microspheres of MnO2-delta consist of nanowires having a diameter of 20-50 nm and a length of 2-8 µm. The value of oxygen vacancy delta estimated from x-ray photoelectron spectrum is 0.3. The magnetization versus temperature curve indicates a magnetic transition at about 13 K. It is found that a parasitic ferromagnetic component is imposed on the antiferromagnetic structure of MnO2-delta, which might result from distortion of the lattice structure due to oxygen vacancies. The magnetic transition temperature TN is about 10 K lower than that of the bulk MnO2 single crystal.
J. Yang et al., "Growth and Magnetic Properties of MnO₂-δ Nanowire Microspheres," Applied Physics Letters, American Institute of Physics (AIP), Oct 2004.
The definitive version is available at http://dx.doi.org/10.1063/1.1805699
Materials Science and Engineering
United States. Department of Energy
Keywords and Phrases
X-Ray Photoelectron Spectra; Ferromagnetic Materials; Liquid Phase Deposition; Magnetic Transition Temperature; Magnetisation; Manganese Compounds; Micromagnetics; Nanowires; Surface Morphology
Article - Journal
© 2004 American Institute of Physics (AIP), All rights reserved.