Ultrasound effects on metallic (Fe and Cr); iron sesquioxides (alpha-, gamma-Fe2O3); calcite; copper, lead and manganese oxides as powders.
Different kind of materials, as powders, were submitted to ultrasound after mixing in water, dodecane or dilute acetic acid (5%). After treatment, firstly a decrease of particle size, and secondly the formation of unexpected and unknown compounds was observed on a mesoscopic scale (CaO from CaCO3 for example). For iron and iron oxides, it was found that the magnetic properties (susceptibility and effective magnetic moment) were changed slightly. A shift in the Morin temperature transition for alpha-Fe2O3 was attributed to the formation of impurities. For inorganic oxides (Cu2O, PbO, Pb3O4 and Mn3O4) sonicated in dilute acetic acid, the formation of metallic acetates is easily achieved and it is rapid (10 s for PbO).
Gasgnier
M
M
Laboratoires de Bellevue, CNRS, Meudon, France. gasgnier@icmo.u-psud.fr
Beaury
L
L
Derouet
J
J