PREPARATION OF BARIUM HEXAFERRITE BY A HYDROTHERMAL METHOD - STRUCTURE AND MAGNETIC-PROPERTIES

Barium hexaferrite, BaFe//1//2O//1//9, was obtained in hydrothermal conditions from a water suspension of alpha -FeOOH and Ba(OH)//2 multiplied by (times) 8H//2O at a temperature about 315 degree C. X-ray and Moessbauer spectroscopy as well as electron microscopy investigations demonstrated the appearance of alpha -Fe//2O//3 as an intermediate phase in the hydrothermal process. The magnetic characteristics of the obtained isotropic magnets are presented. The hydrothermal procedure for the preparation of barium hexaferrite in comparison with the conventional one is discussed.