PARTICLE-SIZE AND MORPHOLOGY OF HYDROTHERMALLY PROCESSED MNZN FERRITES OBSERVED BY ATOMIC-FORCE MICROSCOPY

Atomic force microscopy (AFM) was employed to analyse ultrafine MnZn f errite powders, obtained by precipitation from metal sulphates and sod ium hydroxide at 110 and 190 degrees C, under hydrothermal conditions. Particle sizes measured on AFM images taken at the surfaces of presse d samples ranged from 10 to 40 nm, as a function of synthesis temperat ure, and were in good agreement with measurements made using X-ray dif fraction and the Brunnauer-Emmett-Teller (BET) technique. Direct obser vation a Iso showed that the particles were monodispersed and approxim ately spherical in shape, meeting the requirements for the production of high density sintered components. Using a straightforward sample-pr eparation technique, AFM proved to be a powerful tool for direct analy sis of ceramic powder particles on the nanometre scale.