Synthesis of Hematite Nanowires Using a Mesoporous Hard Template

L. A. CANO; J. F. BENGOA; S. J. STEWART; R. C. MERCADER; S. G. MARCHETTI

La Plata

Conferencia; LAtin American Conference on the Applications of teh Mössbauer Effect; 2008

The properties exhibited by arrays of nanowires and nanotubes are currently intensively investigated because of the new phenomena that they give rise and the wealth of applications that these systems offer. Recently, we have obtained a nanowire geometry by embedding hematite nanoparticles in the hexagonal array of the very narrow channels of MCM-41 [1]. Hematite was chosen as the first step of the preparative methods because its handling is easier than the magnetic iron oxides, maghemite and magnetite. Notwithstanding, the magnetic oxides are more interesting due to their potential applications [2]. Currently we are carrying out alternative experiments to induce the structural transformations that lead from hematite nanowires to maghemite and magnetite nanowires.In this work, we report the synthesis of three samples prepared by wet impregnation of MCM-41 with iron nitrate to yield an iron nominal concentration of 15% wt/wt. Two of them were obtained using an alcoholic solution and afterwards calcined in different atmospheres: air and NO/He. Finally, the last one was prepared with an aqueous solution and calcined in air.