Synthesis, structure and magnetic properties ofβ-MnO2nanorods
1 Energy Nano Material Team, Korea Basic Science Institute, Daejeon, 305-806, Korea
2 Division of Electron Microscopic Research, Korea Basic Science Institute, Daejeon, 305-806, Korea
3 Quantum Material Research Team, Korea Basic Science Institute, Daejeon, 305-806, Korea
4 Institute of Mathematics, Physics and Mechanics, Jadranska 19, Ljubljana, 1000, Slovenia
5 J. Stefan Institute, University of Ljubljana, Jamova 39, Ljubljana, 1000, Slovenia
Nanoscale Research Letters 2007, 2:81-86 doi:10.1007/s11671-006-9034-4Published: 11 January 2007
We present synthesis, structure and magnetic properties of structurally well-ordered single-crystalline β-MnO2nanorods of 50–100 nm diameter and several µm length. Thorough structural characterization shows that the basic β-MnO2material is covered by a thin surface layer (∼2.5 nm) of α-Mn2O3phase with a reduced Mn valence that adds its own magnetic signal to the total magnetization of the β-MnO2nanorods. The relatively complicated temperature-dependent magnetism of the nanorods can be explained in terms of a superposition of bulk magnetic properties of spatially segregated β-MnO2and α-Mn2O3constituent phases and the soft ferromagnetism of the thin interface layer between these two phases.