Mechanochemical synthesis of ferroferriborate (vonsenite, Fe3BO5) and magnesium ferroferriborate (ludwigite, Fe2MgBO5)

Mossbauer spectroscopy and X-ray diffraction have been used to follow the e volution of the phase composition during mechanochemical synthesis of ferro ferriborate (vonsenite) and magnesium ferroferriborate (ludwigite). The pro perties of the compounds obtained have been compared with those of samples prepared by a solid-phase thermal method. It has been established that the samples prepared by the two methods have similar compositions and cation di stributions, but differ in crystallite size, specific surface area and crys tal structure perfection. (C) 1999 Elsevier Science S.A. All rights reserve d.