Growth and magnetic properties of MnO2-δ nanowire microspheres

Yang, J. B.; Zhou, X. D.; James, W. J.; Malik, S. K.; Wang, C. S.
October 2004
Applied Physics Letters;10/11/2004, Vol. 85 Issue 15, p3160
Academic Journal
We report the synthesis of MnO2-δ microspheres using hydrothermal and conventional chemical reaction methods. The microspheres of MnO2-δ consist of nanowires having a diameter of 20–50 nm and a length of 2–8 μm. The value of oxygen vacancy δ 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-δ, 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.


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